/dev/chat - 2019-03-23

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2:30 AM

@sourcejedi - b/c that's a /8 cidr

$ ip -4 a l lo  | grep scope
inet 127.0.0.1/8 scope host lo

3:00 AM

@slm you can't ping 192.168.0.2 if you assign 192.168.0.1/16 to a dummy interface though. That's the magic that is implemented for the loopback range of addresses. I think it's just how the lo interface works on Linux, but that I had difficulty finding the code that implements it to be sure.

3:37 AM

@sourcejedi BTW you fell right into his trap my friend.

1 Q begets 100

@sourcejedi I see what you're saying on these though, on OSX you cannot ping anything but the IP 127.0.0.1 whereas on Linux the entire cidr works.

@sourcejedi Stephen's description of the confusion sounds spot on. All the Q is is a jumble of confusion and Jeff was right to say it should be closed IMO.

loopback and localhost are related but different. localhost is just the name associated to an IP. So that's going through the NS. Try getent ahosts localhost.

8

Q: What is in the output of "getent ahosts"?

What are the fields printed by getent ahosts DOMAIN? The output for getent hosts is a simple combination of IP and hostname. The getent ahosts has an additional third field that is, in all my test, either STREAM, DGRAM or RAW. Output for getent hosts example.net 2001:500:88:200::10 example.net...

networking glibc

1 hour later…

4:52 AM

user image

2

LoL!

3 hours later…

7:23 AM

@Pandya You should read "In the Beginning was the Command Lines". The beginning it. As car analogies go, it's hard to beat.

E.g.

> With one exception, that is: Linux, which is right next door, and which is not a business at all. It's a bunch of RVs, yurts, tepees, and geodesic domes set up in a field and organized by consensus. The people who live there are making tanks. These are not old-fashioned, cast-iron Soviet tanks; these are more like the M1 tanks of the U.S. Army, made of space-age materials and jammed with sophisticated technology from one end to the other.

Though Stephenson himself now uses OS X, I believe.

1 hour later…

8:51 AM

@FaheemMitha ... and nobody knows how to use them, and they keep being replaced by new variants all the time.

@Kusalananda That's demonstrably inaccurate. Well, except for the Kali tanks.

@FaheemMitha Ah, I was thinking that the image was vehicles (=tools) in the field (=Linux).

@Kusalananda Did you look at the actual essay?

@FaheemMitha I've read it at some point in the past, but today? No, sorry.

I thikn I have it on my Kindle, and I think my Kindle is in storage.

Ok.

No, the metaphor is operating systems as vehicles. Vehicles loosely defined.

9:10 AM

@FaheemMitha Operating systems, loosely defined ;-)

3 hours later…

11:46 AM

@Kusalananda If you mean Windows, I agree.

@slm I do care about wtf is up with the ss command though. That was the whole thing about unix.stackexchange.com/a/309089/29483 . And now the man page turns out to be using an entirely mysterious term, and the mysterious distinction between the "socket table" / "address family" options - they don't seem to consistently work as AND conditions, but they don't work consistently as OR conditions either.

12:07 PM

The same question on two SE sites: stackoverflow.com/q/23702202/350713 and askubuntu.com/q/714503/15729

Which is the best answer?

And could we do better?

I'm still not clear why globbing is different from regexes. Isn't globbing basically the same thing, just more restricted?

I looked at it with strace, and ss -A packet_raw doesn't try to read anything.

@FaheemMitha I can't say anything about Windows as I rarely use it.

1 hour later…

1:36 PM

BLASPHEMY

0

A: Added a new user on Ubuntu, set password not working?

I think the easiest method is to use users-admin, a program with a graphical user interface. Install it with the command lines sudo apt update sudo apt install gnome-system-tools

1:56 PM

On Ubuntu, as in Debian, you're supposed to use adduser and addgroup.

I think either should work though

361

A: What is the difference between adduser and useradd?

useradd is native binary compiled with the system. But, adduser is a perl script which uses useradd binary in back-end. adduser is more user friendly and interactive than its back-end useradd. There's no difference in features provided. Source: What's the difference between “adduser...

2:44 PM

I wish there was a better way to convey to users the importance of showing us literally what they are doing and not an approximation. "I can just leave these quotes out of my question, I'm sure they aren't relevant to my issue"

@Jesse_b They're not equivalent. adduser and addgroup is Debian-specific, does more stuff, and is generally the correct way to do things in a Debian-specific environment.

@FaheemMitha According to the ubuntu question I linked, adduser is simply a perl wrapper around useradd

@Jesse_b No doubt. So?

@FaheemMitha So there is no functionality difference between the two, one is just "easier" to use

Basically it automates a bunch of stuff that you need to do.

2:53 PM

I don't necessarily like "easier"

I like understanding the whole process

@Jesse_b Sure there is - it does a bunch of other stuff.

@Jesse_b Hmm, if you want to go the manual route, there are distributions that are happy to take the journey with you. Debian isn't one of them.

yeah this is also why I don't like debian

@Jesse_b That's too bad.

@Jesse_b I don't know if I would use the term easier. Think of it as delegating the details to the computer.

I'm as much in favor of thinking of the details as the next person, but some details are not worth thinking about. And life is too short.

3:13 PM

> The useradd, userdel and usermod commands are lowlevel utilities which are there for historical reasons, while adduser/deluser Do The Right Thing™.

> adduser is more user friendly and interactive than its back-end useradd. There's no difference in features provided.

> If you're writing a script, especially if you aim for portability, you might want to use the lowlevel utilities instead – and adduser/deluser might not be available on all distros, e.g. on SuSE.

I'm not sure if the historical bit is correct, but that's an adequate summary.

@Jesse_b Both friendly and interactive are misleading terms in this context, imo.

friendly doesn't really apply. And I've not noticed those utilities being any more interactive than the Unix norm. Which is hardly at all.

Like the guy says, it does the Right Thing. Stuff that needs to be taken care of, otherwise things won't work as expected.

@Jesse_b Those are Debian-specific.

You wouldn't use them other than on Debian and its derivatives.

I believe they exist on RHEL as well

I always use useradd though

3:28 PM

@Jesse_b If you're on Debian or an Debian derivative, you shouldn't.

3:43 PM

sorry, I wanted to post messages on webapps.SE.

@FaheemMitha Again I will disagree. adduser may be subjectively easier but is functionally no different

@Jesse_b I think I adequately covered that above, so I'm out.

I think your main argument so far has been "it does a bunch of other stuff."

@Jesse_b Yes. Necessary stuff.

Like what?

What does it do that can't be done with useradd

protip: nothing

> With adduser the system level users account when created puts a user directory in home for the system user where useradd does not automatically. If you read the man they are essentially the same except for system level users and associated home directories are automatic. adduser creates a /home/user directory automatically for system level users where there is not a provision in useradd, except if specified by -m option.

alias useradd='useradd -m'

fixed

4:00 PM

From the man page:

> They are friendlier front ends to the low level tools like useradd, groupadd and usermod programs, by default choosing Debian policy conformant
UID and GID values, creating a home directory with skeletal configuration, running a custom script, and other features.

of course there are also several scenarios where you wouldn't necessarily want a home directory so I would prefer the option to decide when the -m option is used

adduser has the --no-create-home option.

What does "running a custom script" mean

I don't think I want that

Also useradd should "conform" to the UID and GID debian policy by default

well maybe not

It will start at 500 instead of 1000

which is good enough for the girls I go out with

@Jesse_b ?

I just think if I'm going to use a wrapper script I'm going to make it myself

4:08 PM

@Jesse_b Well, ok, but not everyone wants to do that. In fact, I suspect most people don't want to do that.

@FaheemMitha Debian specifies UID's 100-999 should be reserved for system accounts. I think that is overkill

Just as most people don't want to compile their own binaries.

@FaheemMitha I suspect the people that want to take the easy road should be using windows

@Jesse_b Does it matter?

I hear they make it very simple to manage users

4:09 PM

@Jesse_b That's a very unfair thing to say.

@FaheemMitha No it doesn't which just works as an argument for useradd

Sigh.

:p. Honestly I mostly do agree with you. adduser seems like the easier way to do it where available but I definitely don't agree that useradd should not be used.

Functionally it's no different it just takes a small amount of additional work and more understanding of the system, both of which I actually prefer

If you want to take the time, sure. It's also possible to write binaries from scratch, maybe even in machine code.

But that is an unfair comparison

useradd with two additional arguments is basically identical to adduser

I think if anything I would recommend someone learn how to do it with useradd at least once and then start using adduser

understand what the UID/GID is and what it should be set to. Learn how to check for duplicates, learn how the home directory is structured and where the skel files are located

4:22 PM

@Jesse_b even if you want to use only 16-bit UIDs and GIDs, reserving the first thousand is still < 2 %.

@ilkkachu Yeah I just don't think I would ever use 899 system accounts, but to be fair I did concede that it doesn't matter

@ilkkachu what about the mkpasswd utility? Is that also bad? I mean I am recommending that user doesn't set the password that way at all

@Jesse_b mkpasswd on my Debian seems to support the SHA2-based hashes (which is good), but it takes the password on the command line (not good)...

oh, right, it has --stdin

"SYNOPSIS: mkpasswd PASSWORD SALT" -- not a very good man page as neither of those is actually a mandatory argument, grr

If I had a dollar for every man page that annoyed me I would have several dollars

2

I can't vote. But my good wishes to @JeffSchaller @ilkkachu @Kusalananda

@PrabhjotSingh thanks!

4:36 PM

@PrabhjotSingh Yeah, thanks!

This could use a column added for UNIX:

[What I expected](https://bloximages.newyork1.vip.townnews.com/tdtnews.com/content/tncms/assets/v3/editorial/6/d1/6d1eafa6-14fc-11e8-85ae-230a943cd4b6/5a8a0079d22d9.image.jpg?resize=1000%2C667)

[What I got](http://images6.fanpop.com/image/photos/39300000/Russian-off-road-vehicles-russian-trucks-39344723-2950-2216.jpg)

Well that didn't work as expected

5:38 PM

@PrabhjotSingh thank you, sir!

6:18 PM

@Jesse_b That array=( $(find ..) ) is gonna break on spaces, and you know it :-)

@Kusalananda replaced with a mapfile

I honestly didn't even think of that though :(. I should read Gilles' why does my shell script choke... answer every 3 months or so

@Kusalananda: I think OP wants to delete only if there are 1000 files older than 1 hour

@Jesse_b Well, I'm uncertain. Their last sentence does read "Here i want to add condition if total files are greater than 1000 then call delete command."

I went with "total files greater than 1000"

6:34 PM

> want to create a shell script that will count files ( 1 hr older files ) and if files are more then 1000

Oh well, OP is taking code from strangers on the internet to delete thousands of files. I'm sure (I hope) they aren't that important anyway :p

@Jesse_b You mean I can't trust code from random strangers on the internet? I'm aghast. Why didn't someone tell me before?

@FaheemMitha I don't even trust code from myself :p

I think I'm a very unlikable person and I can't figure out if I care

6:55 PM

@Jesse_b Weird thing to say.

@FaheemMitha The night shift guy seemed pretty upset with me this morning. My coworkers in general seem to get tired of me eventually though

I think people have too many emotions. They are mostly unnecessary

@Jesse_b Night shift guy?

@FaheemMitha Yeah at work, I have an overlap with him in the mornings

@Jesse_b Life is unnecessary. Or should that be pointless?

@FaheemMitha Maybe, life is pretty cool though. As long as you don't let your emotions get in the way of you living it

7:01 PM

@Jesse_b Upset why?

@FaheemMitha Probably because he missed an alarm the other day and refuted all the excuses for it

Was watching clips of Michael Jackson in concert, on Youtube, with the crowd going hysterical. I remember when I was a child in the 80s, he was all over the place.

I remember those days, when the US seemed such a glamorous place.

@Jesse_b I don't follow. And what do you mean by refuted?

7:18 PM

@FaheemMitha They weren't valid excuses. Not that he was even making them. Our boss was trying to make excuses for him and they were all poor reasons to miss an alarm. The fact is he made a mistake and missed the alarm, which I do not think is a terrible offense but there is no real excuse for it

@Jesse_b What alarm was that?

@FaheemMitha We were alarmed of some services being down on a server, in reality the entire server had become locked up but was still pingable so we never received a server down alarm

@Jesse_b You mean he didn't respond to the notification?

@FaheemMitha correct

Ah. Why not? Did he fall asleep or something? And why did it have anything to do with you?

7:20 PM

@FaheemMitha My boss was essentially asking me to come up with an excuse to give to his boss about it. I think the excuse should have just been "We messed up, wont happen again"

@Jesse_b Sounds messy, but I don't see why you were involved in this.

@FaheemMitha My boss isn't technical and I'm one of the senior people on my team

@Jesse_b Oh.

Though I'm still wondering why he didn't respond to the alarm.

One of my guests recently remarked me that one of the most common causes of stress (he may have said the most common) was work. I think there is some truth to that.

@FaheemMitha I believe it. We are not comfortable wasting the majority of our waking hours to make someone else rich

My biggest goal in life is to make enough income on my own to not rely on an employer

@Jesse_b What would you do if you didn't have to go to work for someone else?

7:29 PM

@FaheemMitha I'm going to try making and selling some wooden crates soon. See where that gets me. There is generally a decent amount of money in reselling products though

@Jesse_b Carpentry? And reselling products? Not sure what you mean. What products?

@FaheemMitha There are a ton of thrift stores near me. Every time I go into one I find a ton of items that would easily sell for double what they are asking online. I am currently working on building a buttload of shelving in my garage to store items while I try to sell them online

I also have been considering buying some additional property to rent out

@Jesse_b Interesting. How can you be sure, though? And what about shipping and insurance?

@FaheemMitha You can make the buyer pay for shipping :p

I think it's quite hard to make a living in the US by being self-employed. Partly by design. For one thing, the income tax situation is very skewed against you.

@Jesse_b Yes, of course. But that makes the item more expensive.

7:35 PM

@FaheemMitha I completely disagree with this. People have this idea but in practice it's actually much more simply than one might think

Income tax isn't very different at all between running your own business and being employed. Sales tax is intimidating but in my experience with it, it's also very fool proof

my city has a very easy to use portal I can log into to pay my sales tax and they have even offered to help me understand it better for free when I was overpaying

As far as the wooden crates I plan to try making both things like this:
https://www.homedepot.com/b/Storage-Organization-Wooden-Crates/Rustic/N-5yc1vZcfzfZ1z0jylj

And like this:
https://www.airsoftstation.com/military-surplus-ammo-crate-wood-w-rope-handles/

Both of which would be perfect to make out of pallet wood which can be obtained for free literally all day long, and I could probably pump out 20 of those in a single weekend

@Jesse_b Well, I've never tried, so I don't know. My mention of income referred to the fact that if you are self-employed, you also pay the tax your employer would pay, if you had one.

@Jesse_b You mean you would make them and sell them? And if so, where?

@FaheemMitha It depends on how your business is set up. As a sole proprietor you only pay one tax. It becomes slightly more complicated if you start hiring employees but generally you will have enough write offs to pay less than you would if you were employed elsewhere

@FaheemMitha I would make them in my woodshop and attempt to sell them in the usual spots. I should get around to putting a website together though, but will mostly put them on the standard buy/sell sites.

7:51 PM

@Jesse_b Oh? Well, I'm not familiar with the US tax situation. As long as you have a good accountant, or know the tax stuff yourself.

@Jesse_b The usual spots? So you like woodworking?

@FaheemMitha Yeah. I have been putting together a woodshop since I bought my house. Prior to that I haven't really done any since highschool where I took 3 years of woodshop classes and 1 year of construction

I know Americans tend to be quite into DIY.

I remember life in the US used to be really busy. I have mixed feelings about that.

8:08 PM

@FaheemMitha I think it depends on the area. Life on the east coast was very fast paced but since I have moved out west I have noticed a huge difference

@Jesse_b I used to live in the NC's Triangle. Hardly a major urban center.

8:25 PM

@FaheemMitha FYI: chat.stackexchange.com/transcript/message/49619217#49619217

@terdon Maybe check if he's actually planning to come to Bombay first.

But thanks for the pointer, or reference, or whatever you want to call it.

@FaheemMitha She, and yes, that's what I asked. I just wanted to make sure you were alright with my linking her to your profile here and your airbnb if she is actually interested.

Oh, you did set up that page? Nice.

@terdon No, it just points to my Airbnb listing.

Yeah, just saw. Still, makes finding it easier :)

Actually, just give her my email address - faheem at faheem dot info.

8:35 PM

OK. I will if she's interested.

My experience is that references practically never work out.

People regularly tell me they are referring my place to so-and-so. And 100% of my bookings are from strangers who clearly don't know me from a hole in the ground.

Wow, 51k? Really?

An female Indian Linux user? Don't think I've ever met one of those.

I mean, I know such people exist.

One of these days I'm going to stay at @FaheemMitha's airbnb

@Jesse_b Unlikely. People say that too.

@FaheemMitha British, actually. But very much not an imperialist.

@terdon Oh. But living in India?

8:43 PM

No, just visiting

Ah

And she's really impressive. She started out at AU knowing next to nothing about Linux and is now among our more knowledgeable users.

Most British people aren't actually imperialists. As far as I know.

Still not the friendliest of people though. By and large. But you already know that.

@terdon Oh? In 3 years?

I did have a British guest recently who was quite nice. A yoga teacher.

@FaheemMitha Pretty much. At least I know I've seen her go from newbie to expert.

@terdon Hmm. That seems on the short side of timeframes for that sort of thing.

8:48 PM

Yep, quite.

9:14 PM

@terdon Seeing that sort of thing happening is really nice.

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