La Salle Debain

Open Source @ Consolidated Braincells Inc.

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About La Salle Debain

This is a weblog I'm keeping about my work on Debian and any other useful Debian related info I come across. It is not meant to compete with other news sources like Debian Weekly News or Debian Planet. Mostly it is just a way for me to classify and remember all the random bits of information that I have floating around me. I thought maybe by using a blog it could be of some use to others too. Btw. "I" refers to Jaldhar H. Vyas, Debian developer for over 8 years. If you want to know more about me, my home page is here.

The name? Debain is a very common misspelling of Debian and la salle de bains means bathroom in French.

If you have a comment to make on something you read here, feel free to write to me at jaldhar@debian.org.

You can get an rss 0.91 feed of the blog here.

Thursday, November 2 2017

New Hackergotchi

The sole purpose of this post is to check my new hackergotchi looks ok on Debian Planet. As I've lost a lot of weight and this is the second Diwali I've managed to survive without regaining, I thought I should update it to a more accurate depiction.


posted at: 23:49:21 | #

Saturday, October 21 2017

Sal Mubarak 2074

Wishing all Debian people a prosperous and auspicious Gujarati new year (V.S. 2074 called Saumya.)

This year fireworks became legal for the first time in New Jersey. Not that it ever stopped us before but it is nice to see the government stop meddling for no reason. (Eff you, Indian Supreme Court.)

Sparklers on Diwali.

Although you can only see sparklers in the picture above, we got enough armament to make ISIS jealous. There were also lots of diabetes-inducing sweets and (inexpensive, practical) presents for young and old. That's what I call a proper Diwali and new year.


posted at: 01:14:22 | #

Wednesday, May 24 2017

For Downtown Hoboken

Q: What should you do if you see a spaceman?

A: Park there before someone takes it, man.


posted at: 23:34:14 | #

Monday, March 6 2017

7DRL 2017

It's time once again for the 7-day Roguelike challenge. This years attempt is entitled "Casket of Deplorables".

Further updates will be posted here.


posted at: 23:52:09 | #

Saturday, March 4 2017

Harshad Numbers

Today while looking up something in my productivity nemesis Wikipedia, I was waylaid by an article on Harshad numbers. (Link goes to Wolfram Mathworld out of spite.) This was interesting to me because Harshad is my patronym. Harshad numbers are also known as Niven numbers but what kind of a crazy name is that? A Harshad number is a positive integer that is divisible by the sum of its' digits.

1-10 are obviously Harshad numbers in base 10. 11 is not because 1 + 1 = 2 and 11 is not divisible by 2. 12 is because 1 + 2 = 3 and 12 is divisible by 3. And so on...you get the picture. Things get even more interesting when you deal with other bases.

Here is a perl one-liner to get the base 10 Harshad numbers from 1 to 100.


$ perl -E '$i=0+shift;for$n(1..$i){$t=0;map{ $t+=$_+0}(split q{},$n);print $n%$t==0?"$n ":q{};}say' 100
1 2 3 4 5 6 7 8 9 10 12 18 20 21 24 27 30 36 40 42 45 48 50 54 60 63 70 72 80 81 84 90 100

posted at: 01:14:27 | #

Sunday, February 5 2017

Don't Believe Everything You Read on Debian Planet

Martin Pitt won the popular vote.


posted at: 23:41:12 | #

Wednesday, November 9 2016

You Know Who Else Won Elections?

[Donald Trump]

You didn't possibly think my streak of serious posts could last did you?


posted at: 01:33:14 | #

Monday, November 7 2016

New Laptop / Problems with Windows part 896,324

I had mentioned previously that I had been forced to purchase a new laptop. I decided that I didn't want another Thinkpad. The Lenovo ones no longer have the high quality they had in the IBM days and while support is still pretty good by todays dismal standards it's not worth the premium price. (If I'm buying it with my own money that is.) I had heard good thing about Dells' Linux support so I looked into their offerings and ended up buying a Precision 7510. Mind you this model came with Windows 7 installed but I didn't mind. As I wanted to install Debian according to my own specs anyway, I was ok with just knowing that the hardware would be compatible. So I prepared a Jessie USB installation stick (This model doesn't have a CD/DVD drive.) and shrunk down the Windows installation (but not deleted it altogether for reasons to be explained below.)

At this point it is traditional to give a long, tortured account of how Heaven and Earth had to be moved to get Linux installed. But that is a thing of the past. The combination of good hardware and the excellent work of the debian-installer team, made the setup a breeze with only a couple of minor bumps in the road. One is that the kernel on the Jessie cd was not quite up to snuff. Downloading 4.6.0 from backports did the trick. Post-install, to get the most out of my nifty new 4K display, I needed the latest, alas non-free, nvidia-drivers. And for stable wifi (I always install over ethernet for this reason) I had to install the firmware-iwlwifi package. Everything else—even my printer—either "just worked" or needed only minor fiddling around.

Having used this machine for a while, the biggest problem I have is with the keyboard. It is nowhere near as tactile and comfortable to use as the old IBM Thinkpads. Even Lenovo Thinkpad keyboards are better. I'm a hunt-and-peck type myself but it is annoying. I think a real touch typist would hate it. The cursor and home, end, page up, page down etc. keys are in the wrong place and home and end are actually function keys. There is a pointer and a trackpad and two sets of mouse buttons which seems like a waste of space. In fact much space is wasted everywhere, space which could be used to improve the keyboard. Other than that I like it. The battery life is not the best but fairly good. It's a bit heavier than I was used to but I've gotten used to it. Although I didn't go with the SSD option, it is not that noisy; again you can get used to it. All in all, I think it is worth it for the price.


I installed Debian but I only really use it as a base to run VMWare Workstation. I occasionally have to support software across multiple platforms but I don't want the hassle or expense of multiple computers so I have Windows (the original installation upgraded to Windows 10) and Mac OS X running in VMs. Plus I have another VM running Kubuntu LTS for my day to day computing, another Debian install running sid for packaging, and Minix. Backups are as simple as making a snapshot of the VM. If something accidently gets screwed up, I can easily revert it back to a known good state. Ideally, I would like to replace VMWare with a free solution such as qemu or virtualbox etc. but as far as I know VMWare is far ahead in emulation capabilities (OpenGL support for example.) which is vital for efficiently using the proprietary OS's.

Things were going swimmingly until a few days ago which brings me to part two of this post. I booted into the Windows 10 VM only to be greeted by a message from the Windows boot manager that "A component of the operating system has expired." I tried going back to a snapshot from September (when this definitely was working) but I still got the same thing. A bit of googling revealed this has happened to others and the advice seemed to be to reset the computers date and reinstall Windows 10. It took several tries but I finally got that done, completed the task I needed to do and shut it down. At the end of the day I shut the whole laptop down and thought no more of it.

The next day I boot up and...where is grub? It seems that during the Windows reinstall, it had overwritten grub with the Windows boot loader. And while grub is nice enough to add an entry for Windows when detected, Windows does not extend the same courtesy to Linux. Ok time to bring out my trusty USB stick again and reinstall grub. Oops I've wiped it off to store other things. No matter, download another image and do it again. Reboot and...back in Windows. Fiddle around in the EFI settings until I can get it to boot from USB.

Now i'm in the shell provided by debian-installer so I can mount and chroot my Linux partition and reinstall grub. Except no I can't because it is Luks encrypted. Ok apt-get install cryptsetup, open it with my passphrase and now I can mount the partion, chroot into and reinstall grub. Except no I can't because it is a logical volume group. Back to apt-get, install lvm2, vgscan (because of course I've forgotten the name of the group,) vgchange and now I can mount, chroot, etc. etc. Except no I can't.


# mount /dev/mapper/vg00-root /mnt
# chroot /mnt
# grub-install /dev/sda
error: cannot find a device for /boot/grub (is /dev mounted?).

sigh


# mount /dev/sda5 /boot
special device /dev/sda5 does not exist.

Well, /dev is mounted but it does indeed not contain a device called sda5.


# /etc/init.d/udev start
udev requires a mounted procfs.  not started.

Very well then.


# mount -t proc none /proc
# /etc/init.d/udev start

Nope. proc needs sysfs.


# mount -t sysfs none /sys
# /etc/init.d/udev start

Still no. You get a warning about how it is a bad idea to run udev from an interactive shell and there is still not /dev/sda5. Time to start googling again. It turns out what I should have done is open another shell from the installer environment and do...


# mount --bind /dev/ /mnt/dev

Now I can mount /boot/grub and reinstall grub and it should all work right?

I should be so lucky. Ok back to square one. I now did what I should have done in the first place and searched the Debian wiki. Sure enough there is a page which deals exactly with my predicament. Finally I get everything installed correctly and triumphantly reboot into Linux.

Of course now Windows doesn't work again...


posted at: 13:01:07 | #

Tuesday, November 1 2016

Sal Mubarak 2073!

Wishing every one a happy Gujarati New Year, Vikram Samvat 2073 named Kilaka and hoping the upcoming year will be yuuge for you.

These next couple of paragraphs are totally not an excuse for why it will take a few more days for me to reach seven blog posts.

Reading reports about Diwali in the American press, I see a bit of confusion whether Diwali is one day or five. Well, technically it is just one (Sunday 30th this year.) but there are a number of other observances around it which could be classed as subsidiaries if you want to look at it that way.

The season commenced last Wednesday with Rama Ekadashi. (where the Gujarati name is different I'll use that and put the Sanskrit name in parentheses.) That's a fast day and therefore not much fun.

Thursday was Vagh Barash (vyaghra dvadashi) which as the name suggests is something to do with tigers but we don't in my experience particularly do anything special that day.

Friday, things began in earnest with Dhan Terash (dhana trayodashi) when Lakshmi the Goddess of prosperity is worshipped. It is also a good day to buy gold.

Saturday was Kali Chaudash (Kali Chaturdashi or Naraka Chaturdashi) On this day many Gujarati families including mine worship their Kuladevi (patron Goddess of the family) even if She is not an aspect of Kali. (Others observe this on the Ashtami of Navaratri.) The day is also associated with the God Hanuman. Some people say it is His Jayanti (birthday) though we observe it in Chaitra (March-April.) It is also the best day for learning mantras and I initiated a couple of people including my son into a mantra I know.

Sunday was Diwali (Deepavali) proper. As a Brahmana I spent much of the day signing blessings in the account books of shopkeepers. Well, nowadays only a few old people have actual account books so usually the print out a spreadsheet and I sign that. But home is where the main action is. Lights are lit, fireworks are set off, and prayers are offered to Lakshmi. But most important of all, this is the day good boys and girls get presents. Unfortunately I have nothing interesting to report; just the usual utilitarian items of clothing. Fireworks by the way are technically illegal in New Jersey not that that ever stopped anyone from getting them. The past few years, Jersey City has attempted to compromise by allowing a big public fireworks display. Although it was nice and sunny all day, by nighttime we had torrential rain and the firework display got washed out. So I'm glad I rebelled against the system with my small cache of sparklers.

Today (or yesterday by the time this gets posted.) was the Gujarati New Years Day. There is also the commemoration of the time the God Krishna lifted up Mt Govardhan with one finger which every mandir emulates by making an annakuta or mountain of food.

Tuesday is Bhai Beeja (Yama Dvitiya in Sanskrit or Bhai Duj in Hindi) when sisters cook a meal for their brothers. My son is also going to make something (read: microwave something) for his sister.

So those are the five days of Diwali. Though many will not consider it to be truly over until this Saturday, the lucky day of Labh Pancham (Labha panchami.) And if I still haven't managed to write seven blog posts by then, there is always Deva Diwali...


posted at: 00:43:15 | #

Friday, October 28 2016

Dawkins Weasel

Happy Dhanteras from Bappy Lahiri

It's already Dhan Terash so I better pick up the pace if I want to beat my blogging challenge before Diwali so in this post I'll discuss a program I wrote earlier this year.


I dread to look up anything on Wikipedia because I always end up going down a rabbit hole and surfacing hours later on a totally unrelated topic. Case in point, some months ago, I ended up on the page of the title. This is an interesting little experiment illustrating how random selection can result in the evolution of a specific form. The algorithm is:

  1. Start with a random string of 28 characters.
  2. Make 100 copies of this string, with a 5% chance per character of that character being replaced with a random character.
  3. Compare each new string with "METHINKS IT IS LIKE A WEASEL", and give each a score (the number of letters in the string that are correct and in the correct position).
  4. If any of the new strings has a perfect score (== 28), halt.
  5. Otherwise, take the highest scoring string, and go to step 2.

I had to try this myself so I wrote a little implementation in C++. A sample run looks like this:

  
$ ./weasel
0000 DNCFICBLUZVC JF KKNVJJASCJRW (0)
0001 DNIFICOLUZVC JFLIKNVAJASCJEW (6)
0002 DNNWICKSUZVCRSFLIKNVA ASCJEL (11)
0003 DNNWICKSUZVCRSFLIKNVA ASCJEL (11)
0004 MNNVICKSQZVCRSFLIKNVA WSCJEL (13)
0005 MENVICKSQZVCRSFLIKNVA WSCJEL (14)
0006 MENVISKS ZTCRSFLIKNVA WLCJEL (16)
0007 MENVISKS ZTCRSFLIKNVA WLCJEL (16)
0008 MEDHISKS ZTCISFLIKNVA WLCJEL (18)
0009 MEDHISKS ZTCISFLIKNVA WLCJEL (18)
0010 MEDHISKS ZTCISFLIKNVA WLCJEL (18)
0011 MEDHISKS ZTCIS LIKTKA WLCZEL (19)
0012 MEDHISKS ZTCIS LIKTKA WLCZEL (19)
0013 MEDHISKS ZTCIS LIKT A WLCZEL (20)
0014 MEDHISKS ZTCIS LIKT A WLCZEL (20)
0015 MEDHISKS ZTCIS LIKE A WLAZEL (22)
0016 MEDHIGKS ITCIS LIKE A WLAZEL (23)
0017 MEDHIGKS ITCIS LIKE A WLAZEL (23)
0018 MEDHIGKS ITCIS LIKE A WLAZEL (23)
0019 MEDHIGKS ITCIS LIKE A WLAZEL (23)
0020 MEDHIGKS ITCIS LIKE A WLAZEL (23)
0021 MEDHIGKS ITCIS LIKE A WLAZEL (23)
0022 METHINKS ITCIS LIKE A WLASEL (26)
0023 METHINKS ITCIS LIKE A WLASEL (26)
0024 METHINKS ITCIS LIKE A WLASEL (26)
0025 METHINKS ITCIS LIKE A WEASEL (27)
0026 METHINKS ITCIS LIKE A WEASEL (27)
0027 METHINKS ITCIS LIKE A WEASEL (27)
0028 METHINKS ITCIS LIKE A WEASEL (27)
0029 METHINKS ITCIS LIKE A WEASEL (27)
0030 METHINKS ITCIS LIKE A WEASEL (27)
0031 METHINKS ITCIS LIKE A WEASEL (27)
0032 METHINKS ITCIS LIKE A WEASEL (27)
0033 METHINKS ITCIS LIKE A WEASEL (27)
0034 METHINKS ITCIS LIKE A WEASEL (27)
0035 METHINKS ITCIS LIKE A WEASEL (27)
0036 METHINKS ITCIS LIKE A WEASEL (27)
0037 METHINKS ITCIS LIKE A WEASEL (27)
0038 METHINKS ITCIS LIKE A WEASEL (27)
0039 METHINKS ITCIS LIKE A WEASEL (27)
0040 METHINKS ITCIS LIKE A WEASEL (27)
0041 METHINKS ITCIS LIKE A WEASEL (27)
0042 METHINKS ITCIS LIKE A WEASEL (27)
0043 METHINKS ITCIS LIKE A WEASEL (27)
0044 METHINKS ITCIS LIKE A WEASEL (27)
0045 METHINKS ITCIS LIKE A WEASEL (27)
0046 METHINKS ITCIS LIKE A WEASEL (27)
0047 METHINKS ITCIS LIKE A WEASEL (27)
0048 METHINKS ITCIS LIKE A WEASEL (27)
0049 METHINKS ITCIS LIKE A WEASEL (27)
0050 METHINKS ITCIS LIKE A WEASEL (27)
0051 METHINKS ITCIS LIKE A WEASEL (27)
0052 METHINKS ITCIS LIKE A WEASEL (27)
0053 METHINKS ITCIS LIKE A WEASEL (27)
0054 METHINKS IT IS LIKE A WEASEL (28)

My program lets you adjust the input string, the number of copies, and the mutation threshold. I also thought it might be interesting to implement the Generator design pattern. In C++ this is done by making a class which implements begin() and end() methods and atleast a forward iterator.

You can find the source code on Github.


posted at: 21:59:28 | #