Ask Ubuntu General Room

Seth

00:05

> When I say my function is safER, I do not mean it is totally invincible. That is impossible in C, and one of the reasons I tell people to not use C anymore. I now firmly believe that C is impossible to write securely and is designed with flaws that are irreparable, mostly because of the huge number of UB that can easily be triggered externally.

That is interesting.. (from Zed Shaw's blog)

Zacharee1

OK

Terrance

@Seth is startup disk creator the same as usb-creator-gtk?

Seth

yes

Terrance

OK, that is what I have been using and it works good for me. :)

Zacharee1

whispers 'well'

:p

Terrance

00:14

Not in front of my computer right now so I couldn't think

Zacharee1

So how are you typing? Telekinesis?

(mobile, I know)

Terrance

Mobile and looking at a very very very tiny screen. :)

Zacharee1

They say telekinesis is a super power, but I'm moving my fingers with my mind right now

@Terrance phone?

Terrance

Yes, it is my phone in the browser

I got a stack exchange message when Seth replied to me

Zacharee1

phone model*?

Terrance

00:16

I'm getting older and my eyes aren't as good any more

Galaxy S5

Zacharee1

Jesus Christ: askubuntu.com/questions/762810/…

@Terrance not bad

He even typed his name in caps!

Terrance

@Zacharee1 I really like the S5. I've used Android since I got the S2 a long time ago.

And never looked back

Wow! I think he likes to YELL a lot.

Zacharee1

I came to the Samsung game too late

Terrance

It's never too late

Zacharee1

Anything above the Note 4 just doesn't work for my needs

Luckily the LG G5 exists

@Terrance I really like having a removable battery

Terrance

00:21

Same

Zacharee1

And high cropping/zoom on the camera

None of the newer Samsung devices have either

Videonauth

I have a Note 3 and im hapy with it since

Zacharee1

Funnily enough, the LG G5's 16MP camera does better in low-light than the S7's 12MP with bigger pixels.

Seth

I'm too picky. I want removable battery, expandable storage, and run Ubuntu :P

Terrance

Samsung got half of it right with the S7 and expandable memory, but missed it with non removable battery.

Zacharee1

00:22

The S7 keeps highlights in check better, but it doesn't pick up as much

Seth

Nothing in the US currently meets that. Nice camera is kinda important too.

Zacharee1

@Terrance yup

They need to introduce a powerusers' series

Terrance

Yes they do!

Zacharee1

Not so shiny or fancy, but functional

Terrance

Exactly!

hbdgaf

00:23

@Zacharee1 if yvette is an SE bot how are her edits not automatically approved?

Zacharee1

@Seth I'm way too picky. Good camera, battery, SD slot, high res screen.....

@hbdgaf watwat?

hbdgaf

Look at the link you posted i replied see the edit history. It required approval

Zacharee1

No, Yvette owns the Ada bot

wow: askubuntu.com/questions/762812/how-to-upgrade-ubuntu-13-04

hbdgaf

@Zacharee1 oh.

Zacharee1

usually it's 15.04 or 14.10, maybe even 12.10, but never the 13s

Videonauth

00:27

hehe @Zacharee1 yeah have recognised this one aswell

Seth

@Zacharee1 13s happen all the time.

Zacharee1

I never see them @Seth

I guess I'm just not online at the right times ;p

Seth

doesn't mean they don't exist :P

Zacharee1

Could you maybe do this for Ubuntu too?

4.3 is almost 2 years old now, MS

Seth

MS doesn't care about linux.

Videonauth

00:32

@Zacharee1 that will take at least another decade till they maintain their code on linux aswell, bethink they just added the bash to windows and this invasion of linux will take time ...

Zacharee1

No, really? @Seth

Mateo

@Seth haha, yeah. Beginers don't need to know anything about make files, barely touched them and can still make scopes with a template project, and some troubleshooting ;)

Seth

make is incredibly complex.. so yeah xD

Zacharee1

So tired

STOP SNIFFING OH MY GOD

People really need to discover the wonderful invention called facial tissue

Seth

at school?

Gentoo on my Tesla

►

anyone wanna play 0AD? I have to go back to doing things tomorrow so this is my last sick day :P

user139252

00:57

@Seth I would, but I can't :(

user139252

I can beat the AI on very easy :p

Seth

that's fine!

:D

user139252

But I am rather busy tonight

Seth

I'm just glad I'm not feeling so bad..

Videonauth

@Seth nice to hear youre feeling better

Zacharee1

01:03

Seth

@Videonauth Thanks. I know I'm quite relieved. It's been a while since I was so sick I couldn't do anything..

Videonauth

sad they build in some jokes so its not good to give to newbs

TheXed

01:20

@Videonauth where are jokes?

Videonauth

ohhhh look for exmple in the first chapter

rm -rf / - makes computer faster

or somewhere later on !whatever:p

TheXed

rm-rf / does make the computer faster, if faster = inoperable...

Videonauth

yeah but now imagine giving that to someone who is really completely new to linux :p

and maybe not a linux which has the protection build in

like ubuntu has

Journeyman Geek

actually that won't totally hose your system any more

Anonymous

hi all

Videonauth

01:24

yeah you would need to add a flag

o/ @onebree

TheXed

what is the command that shos you what programs are running?

Zacharee1

top

Anonymous

Why are so many people having issues with Ubuntu 16? Especially when upgrading from 14 LTS to 16 LTS?

Zacharee1

@onebree dunno

Videonauth

@thexed i find htop mor comfortable but top aswell does its job

Zacharee1

01:27

Maybe it really is a buggy release

Anonymous

I personally have no issue, but I did a clean install.

Zacharee1

No issues on 15.10-->16.04, two very different computers

Videonauth

no issues on 15.10 --> 16.04 either

but ok my hardware is pretty old

SmokeDetector

[ SmokeDetector ] Bad keyword in body, blacklisted website in body: Cech was elected Czech Footballer of the Year by bobgull on askubuntu.com …

Videonauth

wow the smoke detector is slow

Zacharee1

01:31

@SmokeDetector what are they even trying to spam?

Videonauth

i already flagged that one as in need of moderator attention

Zacharee1

@Videonauth there is a spam flag you know

Videonauth

because i wasnt sure if is spam, but for sure not belongs on ask ubuntu

Zacharee1

It's spam

Videonauth

still a hlepfull flag

Zacharee1

01:32

I guess :p

Videonauth

both are going straight for mod's

and gone it is

Zacharee1

yurp

Ubuntu Questions on U&L

0

Q: trying to learn unix stuck on this question

Write a script which will request a user to type in an integer and then guess its square. The script will then either congratulate the user or inform the user what the correct answer is

ubuntu

Ubuntu Questions on U&L

01:55

0

Q: can anyone assist me in what this code does?

I don't know what this code does i am using this forum to assist my learning. for i in $ ( ls ) do [ -r $i ] && more $i done I am stuck with this code i am only learning.

ubuntu

Videonauth

anyone wo has a good link how to make a full customizable and upgradable ubuntu install on an usb stick, maybe im using the wrong search termy but im now at page 40 of google search results and only find how to make live sticks

chaskes

Do you mean like this? askubuntu.com/questions/446682/… @Videonauth

Videonauth

@chaskers kinda just that i want this stick to run on any computer i plug it into

but want tp be able to do upgrades on the stick aswell as sudo apt-get upgrade to keep the system there actual and so on but this article gives me already a general direction

Serg

Well , got writing to serial figured out with no probs, but reading from it is a problem. Prof seems ok with it though

Videonauth

@serg is this maste or bachelor study ?

chaskes

02:08

@Videonauth It'll do all that. it's a normal installation to the usb.

Videonauth

@chaskes ok now only to find out how to do an install from an actual running linux system :) i guess debootstrap is the answer to this ?

chaskes

@Videonauth You can boot from one usb (or a dvd) and install to another. but you can also use debootstrap if for some reason you can't do that. debootstrap is not difficult.

Videonauth

thought so, well its hard i have this laptop running but its dvd drive is in the fritz

i did install ubuntu on this machine with the same usb but now want it not to be an installer media

chaskes

if you have 2 usb slots, that will work fine. but they should be plugged in directly, not on a hub

Videonauth

one usb slot only

debootstrap --variant=????? --arch amd64 xenial /mnt/xenistick archive.ubuntu.com/ubuntu

i use variant = buildd for my sandbox for chroot compiling enviroment

but what to use for a full install

miniso doesnt sound as if it would do the job

chaskes

02:20

Look at the instructions in the installation doc at debian.org. It's very complete and should translate to Ubuntu well. There's also been a couple of answers on the site on debootstrap from ubuntu as I remember. I've only followed the debian instructions.

Videonauth

kk

thank you

chaskes

also, 2 things about a full install on a flash drive 1) if you're going to use it for a long time, you might want to use ext2 since it won't have the journaling constantly rewriting (and skip swap) but ext4 is prob fine but I'm not sure how that will affect the life. 2) Also, it will work best when used on machines with similar hardware.

debootsrap at debian: debian.org/releases/stable/amd64/apds03.html.en

RPi Awesomeness

Windows sucks

I've been using it on my laptop for today because last time I installed Ubuntu the speakers stopped working. Probably a hardware issue, but I'm worried about breaking this RMA one too :P

Videonauth

oh ok, well its more like a system i need when one of my friends calls and has a problem with their machines

this way i can boot their systems without changing anything on their disks and search for the errors or correct them

most people im friend with are more DAU's

and have not much clue about their pc's

so if something is wrong they usually call me

chaskes

that sounds like it will work fine then. you might also try knoppix for this.

Videonauth

02:31

ok thank you very much for your lenthly and informatiev answers and your patience with me

chaskes

hmm it's easiest to install knoppix to a usb if you boot it from a dvd first, which you can't easily do right now, but check the instructions.

you're welcome. we all love doing this

Videonauth

oh i will find a way for sure now

chaskes

knoppix is very cool, is based in debian, and uses an on-the-fly compressed persistance drive on the usb so it can hold more than the size of the usb

and designed for installation to the usb

Videonauth

sounds good will look into that

Terrance

knoppix was one of the first Linux live distros I was introduced to, and I loved it! =)

chaskes

02:37

yeah, still love it. 7.7 just came out.

Terrance

It says 7.6 is released now. :)

4.2.2 kernel, but that's fine.

I don't think the 4.4 kernel has had as much testing yet.

chaskes

(4.7 was typo). 7.7 just came out on Linux Pro mag disc. Sometimes he puts a new version on the mag disc before he puts it on his site

Terrance

Ah, Cool!

I am thinking I am going to have to download at least the 7.6

Videonauth

weird i only find 7.2 on the mirrors

chaskes

did you go to the main site?

Videonauth

02:42

knoppix.org

but it seems not all the mirrors have 7.6 or 7.7

Terrance

The torrent is working great for the download. =)

Videonauth

0

Q: Lamp on Ubuntu 16.10 by 32 bit laptop

I have problems to setup my lamp-server in Ubuntu 16.10. On previous versions I followed the tutorial http://howtoubuntu.org/how-to-install-lamp-on-ubuntu successfully. My laptop is 32 bit. Is it possible the new PHP7 isn’t working on 32 bit computers? Or will the problem be something different?

16.04 32-bit lamp php7

chaskes

@Seth Here's article you'll like about MS and open source linuxjournal.com/content/death-robovm

Videonauth

wow i want to know where they all got their handds on 16.10 already

Terrance

??? That is a good question! :P

Videonauth

02:45

guess they all own DeLoreans :p

Terrance

=)

chaskes

16.10 is available as a daily build already

Videonauth

yeah but ... well

that would be more than bleeding edge to install it right now

Terrance

No thank you! I'm sticking to the LTS releases.

Videonauth

only thing which is on my system not ubuntu serial is the kernel whi is for me acuall 4.6 RC 4

chaskes

02:49

if you want to play with it (and report bugs) just make another partition or a vm for it

Videonauth

and my hard guess would be that even if i would pack it into a deb file it wouldtn run on any other system as this one

Terrance

@chaskes Yeah, I can do that much, but not for actual installation on my system. :)

Videonauth

do you have alink to the daily release ?

Terrance

cdimage.ubuntu.com/daily-live/current

Seth

@chaskes mm, yes. Very good. Thanks for the share.

TheXed

02:56

Any crontab experts?

Seth

I'm an expert at reading documentation, does that count? :P

chaskes

@Seth Linux Voice is a very good mag

They've also (from what I read) destroyed CyanogenMod

Seth

How so? It seems to be doing just fine..

TheXed

@Seth I thnk I figured it out...thanks anyways

Seth

patent trolling?

@TheXed np

chaskes

03:01

I forget the exact deatils, but maybe destroyed was the wrong word. I mean from a foss point of view. I believe they have a controlling share and are closing it up and using it as a source for trolling

TheXed

if I want to ssh into a device but I want to specify the port (changed it from port 22) how do I do that?

chaskes

This is a neutral article arstechnica.com/gadgets/2016/02/…

TheXed

in other words how to I ssh into a non standard port via the terminal?

Videonauth

ssh l username -p 12345

-p for portnumber

TheXed

@Videonauth thank you.

Videonauth

03:05

npyvw

chaskes

@Seth Actually, a lot of the articles seem to take Cyan/MS at their word that they want to open up the Google-only parts of Android. But I don't see how MS taking over cyanogenmod could really be a positive in the long run. They just try to replace Google-controlled with MS-controlled. but not with foss

Seth

@chaskes MS wants to acquire cyanogenmods?

chaskes

@Seth They've invested $70 million in a strategic partnership arstechnica.com/gadgets/2015/04/…

Seth

huh, interesting.

Videonauth

03:55

soooo download of yaketey yak done now installing on a VM and then lets see :)

mhmmm same result as if i started the 16.04 cd on my windows machine VM

Seth

that was a bug in 15.04 or 15.10.. I forget exactly how it works.

Videonauth

04:11

weirdly 15.10 stearted properly up and was able to install on my windows workplace VM

Seth

lemme see if I can pull it up.

Videonauth

from there i upgraded to 16.04

and this result here is now on a linux machine virtualbox

Seth

Take a look at this Q:

89

Q: Ubuntu 14.10 does not install in virtualbox

I'm currently running Windows 8.1 x64 (a problem in itself that I can't change sadly ;-P) with the latest version of VirtualBox (4.3.18 r96516). I managed to get the server version up and running with no issues but I cannot get the desktop version running. I can boot to the menu and start the p...

system-installation virtualbox resolution 14.10

Apparently it was 14.10.

Videonauth

mhmmm ok lets see if this fixes it

yep that fixed it

thank you

great to see the guy who answeed this questioin did 1220 rep points alone from that answer

Serg

LightDM is a baaaaaad stuff

0

A: I accidentally typed my password into the login field, is it still secure?

In your case, you are safe - you've typed in a password and cancelled out of it. A password typed into login prompt followed by wrong password will be considered failed authentication and is partially recorded to btmp log. For tty console that's however alright. $ sudo lastb ...

If you accidentally type in your password ( which I've done couple of times at the GUI ) it will record your failed login attempt . . . so part of the password will be recorded

user139252

04:26

Migrating the main Pi to a new SD card. Wish me luck.

Serg

@TheBrownOne fingers crossed

Videonauth

well for one thing linux is great, it makes you remember your 15 character random password within a day lol

zb'Id7Wg)/<jvtl <-- this is how my passwords usually look like

Serg

O_O

how on earth do you remember something like that ?

My passwords are usually in chinese with some funny numbers

Videonauth

i write it down on a paper then use my linux machine a day long including all sudo working and so on then i have it in my physical memory and burn the paper

means i not remember the pass itself i only remember the finger movement

Serg

that's some awesome stuff . . . some james bond type of stuff

Videonauth

04:34

after a data security homepage it will take about 42 billion years to brute force that password with 2 billion tries per second

Seth

I generally take a sentence and cut it into letters.

Throw in a few numbers and special characters.

user139252

...Lame.

Videonauth

thre was a time i used 1337 speak for my passwords but meanwhile there are dicts for that too

user139252

I have Python generate a random 12-18 character password for me and then create a mnemonic.

Videonauth

the longest passords are on my router and so on

they are 64 characters random

Serg

04:37

My logic is that most english-speaking blackhats expect english words

Videonauth

those i have on an usb stick i keep on my person

Serg

so if I ever get hacked, that will be by chinese folks . . .their dictionaries probably have the words i use

Videonauth

@serg ther youre wrong they meanwhile running multilingual dicts

Serg

some of them probably do

Videonauth

that what i do as hobby and sometimes hired as a freelance, digging in offensive security

Serg

04:39

so you're a pentester

Videonauth

yeah kinda

and a security consultant

Serg

nice , I've only played a bit with hydra , nmap, and tcpdump. Got wireshark once but never played with it much

I've poked around computer security info here and there, but for the most part my knowledge is limited

Videonauth

weirdly the very first tool you always use over the net is nmap :)

then if theres a website see if code injection works

or if there other holes to poke into use them

Serg

yup, it's quite useful. By the way, I've found out that one of our ex students in university actually became one of maintainers or something for nmap

Videonauth

biggest nicest distro i can really recomment is th new kali rolling

buts really nothing for much customization

custommization on kali linux most likely will break it

like adding ppas and so on

Serg

04:44

Kali doesn't get much love on the askubuntu and U&L though

Videonauth

sad it is heaviliy maintained and always bleeding edge

but ok most people work iin production enviroments where rolling releases ar not wanted

Serg

Well, it's mostly because of all the script kiddies who install kali or backtrack, and then thing they're l33t hackers till something breaks

Videonauth

yeah well i did a long time the hacking myself game

Serg

And I do think it deserves attention as other Linux distros . . .

Videonauth

set up a dedicated webserver which i share with a friend and hacked it

user139252

04:47

@Videonauth Want to have some fun trying to break my server after I reboot it with the new SD card?

Videonauth

this way i gained my knowledge about possible holes to use and so on

Serg

Somebody is trying to connect TI-89 calculator as serial console

wow . . .

Videonauth

i@the brown one not without a contract :) just because i stay strickt on the white side i have to make sure i have paperwork for every hack i do

@TheBrownOne

here in germany you can go up to 10 years to jail for hacking so i stay rather on the safe side

Serg

Well, technically there can be issues with that in the US too. As long as everything consensual , it's all good . . . just like sex

Videonauth

just like sex the girl later acuses you to have raped her and your in trouble ..

Serg

04:52

That's why there should be documentation and proof ;)

Videonauth

this is why i stay away of thing which syntax i dont understand :))

and girls hav definetively a special syntax i cant grab really

and they have no power off button

Nathan Osman

@Serg Then there's this:

Working on getting the shell from my Raspberry Pi to my calculator. And it's working :) http://t.co/BGZcY4zUOe

Tweeted by williamtdr on December 9, 2014 at 1:51 AM

Seth

@NathanOsman WHY

Nathan Osman

I guess the best answer to that is "because he can".

Serg

@NathanOsman that's the best answer of them all :)

@Videonauth yeah . . . but they're cute and pretteh

Videonauth

04:58

@serg i still have to come across one which is worth my attention

Serg

@Videonauth Chinese say 天下无双， there is a pair for everyone. Eventually you will come across

Videonauth

yeah i guess this is true

Pandya

I want to download all the images that are displayed by reader in webpage: scribd.com/doc/207110303/…

How can I?

with httrack ?

Videonauth

askubuntu.com/questions/762896/…

Serg

@Pandya screenshot them all ?

Pandya

05:02

@Serg Though I can download then with Save as image (actually they are jpg(s)).

but there are 527 pages. So it is time-consuming to do for all separately

so, I am looking for helpful tool

user139252

Everything works after the migration :D

Videonauth

-2

Q: Dropbox customer support service (1888-2595-888)

Having problems with Dropbox home or Dropbox businesse like Unable to share and sync Files and folders with Dropbox, Dropbox Update issues, Dropbox does not Launch etc. Our 24x7 Dropbox Technical support number 1888-2595-888 can help you to troubleshoot all kind of Dropbox issues very efficiently...

dropbox support

this one the smoke detector didnt get

flagged it

user139252

@Videonauth Does an email saying you're allowed to do it for fun count? :P

Pandya

@Serg have you visited the webpage?

Videonauth

@TheBrownOne not with the german legislation, emails are here still no viable legally proof

Serg

05:05

@Pandya yeah, I have. The source of the web page has links to some jpgs

You probably could curl the source, then extract all the urls of images , and wget them in a for loop

anywho . . .i need a drink and maybe a nap

user139252

@Serg Nope, curl doesn't yield the links in the source.

Pandya

Hmm. I found them are under https://html1-f.scribdassets.com/4i0ucbv4hs3hukjz/images/ & https://html2-f.scribdassets.com/4i0ucbv4hs3hukjz/images. let me try a flashgot addon

Serg

@TheBrownOne yeah, you're right. NEither does wget . . . dang it

user139252

@Pandya Just tried, going to get an "access denied" error

Videonauth

@Pandya maybe an offline browser tool !?

Pandya

05:12

@TheBrownOne what have you tried?

user139252

I think the frame has some kind of authorization built into it

user139252

@Pandya Every method available to to to get to those directories :P

Videonauth

then you could extract the images from the cache of this

Ask Ubuntu Meta

0

Q: How to Post threads

How can I post a thread on a Ubuntu forum? Also, what the hell is a Tag? I can't even ask a question without going to school for questions.

discussion

Videonauth

@Tim wonderfull answer +1

Pandya

05:23

how about this?

Videonauth

only one way to find out if it works, press ok

Pandya

seems working.....

but only 145 files

If you know helpful method for getting the frame :P then introduce.

And by the way, what is httrack equivalent of chat.stackexchange.com/transcript/message/29257696#29257696 ?

blade19899

07:51

The Meizu PRO 5 Ubuntu Edition is now available!

Also within Rusia

Stefano Palazzo

The specs sound great

Videonauth

08:18

can you go into tty inside a guest session (default guest acout) ?

terdon

Close as non-reproducible please.

i do the same work that i have done before,but this time it works!!!!! thanks a lot and sorry bothering you. — samira 16 hours ago

@Videonauth I don't see why not.

Videonauth

ok asked because i wanted to comment on that here

0

Q: Recover data from a Guest Session

I gave a job candidate a short coding test using a guest session on a Laptop with Ubuntu. When I opened the guest session I saw the message: After the interview I closed the lid of the laptop to transport it to another room. I did not explicitly log out. When I opened the lid, of course, it ha...

data-recovery guest-session

terdon

@Videonauth Ah, but if closing the lid logged him out, the data won't be there. Dropping to a tty makes no difference, it's just like using a GUI terminal.

Videonauth

oh ok, good to know guess i never stop learning

well better to delete my comment then :)

weird really if i really would be concerned about security on a laptop i would simply make a clean install give that laptop to an applicant and then when i seen all i would reset by doing a new clean install

or set up VM's

Thijser

09:35

Hello people, quick (slightly noob) question:

I have a proccess where I would like to kill the proccess and all children, ctrl - z and -c don't seem to do this, how do I properly do this (both leave ports in use)

terdon

@Thijser kill

Thijser

no easy shortcut on the proccess itself (just managed to kill myself)

terdon

@Thijser ?

What do you mean on the process itself?

You can use killall foo or kill $PID. You can also use kill -TERM -PID where the PID is the group parent PID. For more details, please ask on the main site giving a specifgic example of what you need.

Thijser

09:53

Well I have a proccess that I start (let's call it P)

So I go into a terminal and just type in P

now the proccess is runing

but P has launched 10 children each of which bind to a port

now I would like to free all ports and stop P

so I press ctr-C

but the ports remain in use

terdon

OK, the details depend on what P is and how it works. In many cases, Ctrl+C will stop it.

Still, as I asked before, please post a question on the main site.

The answer will involve kill -PID as I mentioned above but this sort of thing really should be on the main site.

Thijser

Alright was just hoping that there would be an easy method

0

Q: How to kill proccess that spawns several java programs that each take a port

I have a program .sh that spawns several child proces like so: javac *.java rmiregistry 3300 & sleep 5 java Node 3300 3001 1 & sleep 1 java Node 3300 3002 1 & sleep 1 java Node 3300 3003 1 & sleep 1 java Node 3300 3004 1 & sleep 1 java Node 3300 3005 1 & Now When I run this in a terminal scr...

java kill

Videonauth

@JacobVlijm do you want to have a look at my answer here to see if i missed something? askubuntu.com/questions/762972/…

muru

8

Q: Kill all background jobs

Is there a more compact form of killing background jobs than: for i in {1..5}; do kill %$i; done Also, {1..5} obviously has a hard-coded magic number in it, how can I make it "N" with N being the right number, without doing a: $(jobs | wc -l) I actually use \j in PS1 to get the # of managed...

bash

terdon

@Thijser OK, see, what you're doing is much more complex than you said here. OK, hang on.

terdon

10:16

@muru That won't work here.

muru

@terdon in a signal handler for the script

trap SIGINT, kill jobs

terdon

The background jobs won't be visible in jobs though, will they?

muru

Within the script, they should be

terdon

@Thijser wants to launch a script that launches backgrounded jobs and then kill all of the launched jobs from outside the script.

muru

Does it have to be outside the script?

terdon

10:20

@muru I guess so. There's not much point otherwise.

It's very simple to do though. You just need kill -TERM -PGID

Small Legend

Hi guys I'm using wget to download a series of different files sizes. Any idea why the throughput is generally lower for smaller files?

terdon

0

A: How to kill proccess that spawns several java programs that each take a port

The way to kill all the jobs launched by a process is to use the process group ID (pgid). The simplest way to see that it to launch your script in the background: $ launch_java.sh & [1] 25649 The number printed above is the PID of the launch_java.sh which is also the group ID since that launch...

@SmallLegend You mean the speed? It should be faster.

Small Legend

It downloads faster of course, but the throughput is less

muru

Lots of time wasted opening, closing, creating files. On both ends.

terdon

@SmallLegend What do you mean by "throughput" in this context?

Small Legend

10:26

For example, a snippet of a large file 0K .......... .......... .......... .......... .......... 0% 544K 3m13s
50K .......... .......... .......... .......... .......... 0% 1.07M 2m24s
100K .......... .......... .......... .......... .......... 0% 45.4M 97s
150K .......... .......... .......... .......... .......... 0% 47.2M 73s
200K .......... .......... .......... .......... .......... 0% 1.08M 78s
250K .......... .......... .......... .......... .......... 0% 49.4M 65s
300K .......... .......... .......... .......... .......... 0% 33.4M 56s

and a snippet of a small file
0K .......... .......... .......... .......... .......... 46% 546K 0s
50K .......... .......... .......... .......... .......... 93% 1.06M 0s
100K ...... 100% 22.8M=0.1s

Not the best example but the general throughput is smaller for the smaller file, why is this?

terdon

@SmallLegend You keep repeating the word "throughput" and refuse to explain what you mean by it. Are you referring to the speed? MB/s?

Small Legend

Yeah sorry I am @terdon

For example a large file downloads at 16.9MB/s wheres as small file does 4.2MB/s

Oli

10:51

@SmallLegend There is overhead in setting up a connection. It usually isn't much, but it exists.

If there's transparent compression too (eg gzip), bigger things tend to compress better. So what's 100MB at the beginning might actually only be 10MB in transfer, while the smaller file might be proportionally bigger.

That does hugely depend on the content of each.

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