Posts Tagged ‘course’

Must have software on freshly installed windows – Essential Software after fresh Windows install

Friday, March 18th, 2016


If you're into IT industry even if you don't like installing frequently Windows or you're completely Linux / BSD user, you will certainly have a lot of friends which will want help from you to re-install or fix their Windows 7 / 8 / 10 OS. At least this is the case with me every year, I'm kinda of obliged to install fresh windowses on new bought friends or relatives notebooks / desktop PCs.

Of course according to for whom the new Windows OS installed the preferrences of necessery software varies, however more or less there is sort of standard list of Windows Software which is used daily by most of Avarage Computer user, such as:

I tend to install on New Windows installs and thus I have more or less systematized the process.

I try to usually stick to free software where possible for each of the above categories as a Free Software enthusiast and luckily nowadays there is a lot of non-priprietary or at least free as in beer software available out there.

For Windows sysadmins or College and other public institutions networks including multiple of Windows Computers which are not inside a domain and also for people in computer repair shops where daily dozens of windows pre-installs or a set of software Automatic updates are  necessery make sure to take a look at Ninite


As official website introduces Ninite:

Ninite – Install and Update All Your Programs at Once

Of course as Ninite is used by organizations as NASA, Harvard Medical School etc. it is likely the tool might reports your installed list of Windows software and various other Win PC statistical data to Ninite developers and most likely NSA, but this probably doesn't much matter as this is probably by the moment you choose to have installed a Windows OS on your PC.


For Windows System Administrators managing small and middle sized network PCs that are not inside a Domain Controller, Ninite could definitely save hours and at cases even days of boring install and maintainance work. HP Enterprise or HP Inc. Employees or ex-employees would definitely love Ninite, because what Ninite does is pretty much like the well known HP Internal Tool PC COE.

Ninite could also prepare an installer containing multiple applications based on the choice on Ninite's website, so that's also a great thing especially if you need to deploy a different type of Users PCs (Scientific / Gamers / Working etc.)

Perhaps there are also other useful things to install on a new fresh Windows installations, if you're using something I'm missing let me know in comments.

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Command to get CPU server load in % percentage using bash and /proc/stat on Linux

Wednesday, March 11th, 2015


Getting load avarage is easy with uptime command, however since nowadays Linux servers are running on multiple CPU machines and Dual cores, returned load avarage shows only information concerning a single processor. Of course seeing overall CPU server load is possible with TOP / TLoad command  / HTOP and a bunch of other monitoring commands, but how you can get a CPU percentage server load using just  /proc/stat and bash scripting? Here is hwo:

:;sleep=1;CPU=(`cat /proc/stat | head -n 1`);PREV_TOTAL=0;for VALUE in "${CPU[@]}”; do let “PREV_TOTAL=$PREV_TOTAL+$VALUE”;done;PREV_IDLE=${CPU[4]};sleep $sleep; CPU=(`cat /proc/stat | head -n 1`);unset CPU[0];IDLE=${CPU[4]};TOTAL=0; for VALUE in “${CPU[@]}"; do let "TOTAL=$TOTAL+$VALUE"; done;echo $(echo "scale=2; ((($sleep*1000)*(($TOTAL-$PREV_TOTAL)-($IDLE-$PREV_IDLE))/($TOTAL-$PREV_TOTAL))/10)" | bc -l );


As you can see command output shows CPU is loaded on 52.45%, so this server will soon have to be replaced with better hardware, because it gets CPU loaded over 50%

It is useful to use above bash shell command one liner together with little for loop to refresh output every few seconds and see how the CPU is loaded in percentage over time.


for i in $(seq 0 10); do :;sleep=1;CPU=(`cat /proc/stat | head -n 1`);PREV_TOTAL=0;for VALUE in "${CPU[@]}”; do let “PREV_TOTAL=$PREV_TOTAL+$VALUE”;done;PREV_IDLE=${CPU[4]};sleep $sleep; CPU=(`cat /proc/stat | head -n 1`);unset CPU[0];IDLE=${CPU[4]};TOTAL=0; for VALUE in “${CPU[@]}"; do let "TOTAL=$TOTAL+$VALUE"; done;echo $(echo "scale=2; ((($sleep*1000)*(($TOTAL-$PREV_TOTAL)-($IDLE-$PREV_IDLE))/($TOTAL-$PREV_TOTAL))/10)" | bc -l ); done



To monitor "forever" output from all server processor overall load use:

while [ 1 ]; do :;sleep=1;CPU=(`cat /proc/stat | head -n 1`);PREV_TOTAL=0;for VALUE in “${CPU[@]}”; do let “PREV_TOTAL=$PREV_TOTAL+$VALUE”;done;PREV_IDLE=${CPU[4]};sleep $sleep; CPU=(`cat /proc/stat | head -n 1`);unset CPU[0];IDLE=${CPU[4]};TOTAL=0; for VALUE in “${CPU[@]}"; do let "TOTAL=$TOTAL+$VALUE"; done;echo $(echo "scale=2; ((($sleep*1000)*(($TOTAL-$PREV_TOTAL)-($IDLE-$PREV_IDLE))/($TOTAL-$PREV_TOTAL))/10)" | bc -l ); done



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Can you swim after communion? – What is better not to do after receiving the holy sacraments

Tuesday, July 29th, 2014

I took the sacraments this Sunday, and as we're on a holiday and we go to swimming daily. I never swim eucharist in my wife, so a logical came is it allowed to swim after receiving the holy sacraments?

I've googled around to see for an answer but it seems from what I find there is no official plain answer telling whether swimming is allowed or not after communion.

As there is no official church position on this question, this question is solved privately with your priest (spiritual father), if you have such, if not you can do it according to your own conscious.

I've red there are some priests who say, the best practice is not to swim after communion at least 9 hours after holy communion.

For monks the question to swim or not after receiving the holy sacraments is clearly answered as monks are not allowed to go to a beach / undress or wear a swimwear. The reason for that swimming could turn to pleasing the flesh and even a passion in some cases.


For layman swimming is allowed, but it is dangerous to swim for the only reason, one can hurt himself during swimming and there might be bleeding and it is well known rule to try to follow not to have bleeding or open wounds during communion. Of course in some cases for old people who believe and take the holy blood and flesh of the Lord Jesus Christ with permanent open wounds this rule cannot be observed and with such there might be exceptions. But the general rule for healthy people to follow is to preserve themselves from bleeding after receiving holy communion.
Also an interesting thing that is good to observe after communion is not to take haircut on the same day, cut nails and even it is recommended to not take shower the same day.
The reason to generally try to not wash the body is because the blessing and renewal of the body by the holy spirit which is received in form of Christ's blood and flesh is bathing us and we don't want to wash out this blessing.


Of course to shower or not after communion is a personal decision. Also the one of the reasons not to haircut on same day as holy communion is it is usual to get a shower after haircut and it is better not to do that. No bleeding on the same day as communion is because we physically receive holy Christ's body and flesh and his holy gifts run through all our body including in the blood and we don't want to have to waste and "spill" this grace through bleeding.
Also on day of receiving holy sacraments it is church rule not to kiss, not to spit and walking barefoot (for the danger that you can hurt yourself and have a blood spill).


If for some reason you fall and bleed the proper way to deal with the situation is to burn the tissue with the blood.

The number 9 hours to wait is significant in that it reminds us of the hours our Lord Jesus Christ spent to pay our debts with his holy blood and thus grant us salvation. This is the way of the cross starting from 9:00 AM – 6:00 PM, the trial, crucifixion, death, and laying in the tomb took a total of 9 hours.
Also trying consedering not to spit, not chew chewing gum, wash, take shower and kiss is important as it is a mean of watchfulness and as Christians we have to be watchful, at least some minor time after being allowed to re-join the Holy Body of Christ through the holy sacraments gifts in Church.

If you're bringing to communion your kids it is a different story and you can be less vigilent to obseve all this, as it is impossible to know what a kid could do.
It should be known except spitting, right after receiving the holy communion all is not a must observe rules but it is good ones to follow.

Most of the information of this post is based on Coptic Oriental Orthodox forum with questions and answers on wha it is better not to do after communion, anyways as we Eastern Orthodox Chrsitians are so close in faith to Copts, the answers there are true for us too.

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Color Trick Microsoft and Google use to keep their users loyal and happy unwalfully

Tuesday, June 12th, 2012

Color mind influence has been longly researched. It is researched and there are some findingings on how we people react on colors. This researches are not much known and most of them are not put on the internet (??) One model claiming to have explained how colors influence is called HBDIHerrmann Brain Dominance Instruments.

In the picture beginning of this post, I have presented a quick "Personal Profile" of HBDI on how one think in order to determine in "which colors" one tends to think more ___

In short HBDI model claims to explain how people think in another model.
My personal view of it is it is like most science nowdays more based on faith than on a clearly conducted scientific research and facts. We know pretty well many people tried to explain how brain operates and many people give models to explain it however none of the models could grasp in completeness the complexity of human brain. Hence Businessman people who use this model in their daily life and they push it to us has put the model in action not that they know it is working but rather they believe it does .., Saying this few words as introduction I will contninue onwards to explain you about HBDI as in the business world it is considered as a "Strategic Asset" for a company success. Hence the use of richest companies of the model has a serious impact on us the common people and unknowing (uninformed) computer users.

Some of the companies who integrated the HBDI to their models we all know are of course not strangely Microsoft and Google

Below I present you a picture showing the HBDI The Whole Brain Model |||

HBDI The whole brain model

Next I show you Microsoft Windows OS worldly "infamous" flag |||

Microsoft Windows OS Flag

You can see for yourself the basic color from HBDI WHOLE brain model are integrated in the Microsoft flag, only the order of colors present and the color gamma is different;;;;

The basic colors in HBDI model to explain how human brain works is separated in 4 segments as you can see from above screenshot. There are a number of tests one can do to determine what is his exact HBDI profile, and in abstract terms in which kind of colors he prefers to think.

There are a whole "army" of people involved into this sect like philosophy (I call it philosophy as surely every model that tries to explain everything is doomed to fail it is the nature in which God created the universe so complex and he put us be part of it and not controllers of it that any Universal model trying to explain it has never succeeded so far. The HBDI has some fruits for the only reason it is believed to work well by the people with money.

As you see in the colors HBDI claims there are 4 segments corresponding to four basic colors

  • BLUE
  • RED

Each of the colors is an indicator on how the person tends to think the BLUE people as HBDI practicioners (believers) calls them are —

Analytical, Fact Based, Logal, Quantitative

The YELLOW oriented people are claimed to be —

Holistic, Intuitive, Integrating, Synthesizing

The GREEN ones in model terms are interested in —

Organizing, Sequentiality, Planning, Detailizing facts

Finally the RED Ones are said to be —

Interpersonal, Feeling based, Kinesthetic, Emotional

Now as you can understand this model though it looks like promising is based on a philosophy which rejects the existing of spirit realm God Angels or good or evil. It claims everything we're are or we want to be can be achieved following the HBDI to develop your own brain.

This model as every human made model however does reject the fact that besides internal factors and brains we're put into external environment most of which we cannot control and therefore even if we try our best to have certain goals and complete them the external uncontrolled facts can be a reason to stop us to complete our goals.

Now back to my point, that Google, Microsoft and probably many other products and physical goods are heavily using the HBDI color scheme ;;;
Here is the Google Inc. Logo the color trait of HBDI is there:

Google Search Engine Logo and HBDI 4 colors embedded

For those doubting that Google Inc. and Microsoft Inc. are along the false believers of HBDI color scheme brain ideology I present below the Logo of Google Web Browser =- Google Chrome

Google Web Chrome Browser Logo 4 colors HBDI microsoft flag

It is evident 4 colors used as a main ones in the HBDI tool are present in Google Chrome just like in Microsoft Windows logo flag, the only difference is in the order of colors.
Also it is interesting the name Chrome that Google Chrome took is most likely taken from Aldous Huxley's – Brave New World (A book depicting a short future highly conditioned society) , the book story line goes around a society programmed to do the things they do.

I assume it is very likely that Google's founders Sergey Brin or some of their subordinate working for Google are very much into the idea of conditioning people just like in the book and this is most likely the reason they choose the Chrome as a title for Google's browser ,,,

The 4 Colors from HBDI yellow, green, blue, red are embedded also in the google .ico file (the little icon showing in browser URL bar), below is a screenshot of a tab where google is opened showing the .ico image:

Google Icon 4 colors Linux Debian Epiphany Browser tab screenshot

Do you remember the good old Windows XP start button, have you noticed the Windows flag embedded in it, if not let me show you;;;

Microsoft Windows XP Start Button and HBDI 4 colors scheme

But wait the Windows flag placed on the left bottom of Ms Windows-es is not only on XP it is also on Windows 3.11 cover, Winblows 98, Vista, Windows 2003, Windows 2007 and actually all the M$ operating systems ever produced since the very early days M$ become a top OS producer :::

Windows 3.11 Operating system logo flag

Microsoft Windows 95 4 colors flag and blue sky

Here is also the 4 colored (a bit like Nazi like looking) flag on M$ Win-doze 7 |||

MS Windows 7 start Menu m$ windows well known flag

Also the Microsoft Flag is positioned on the bottom left screen on purpose. It is well known fact that most of the world (except Arabic) are used to read the text from Left to Right

, therefore it is natural for our eyesight to look for the text on the left side. I just wonder why they placed the START on the bottom and not on top. It is natural we read text and books from the most top to the most bottom ,,,.,

Even Apple Computers nowdays Macs has most likely used the HBDI as the main 4 colors and some gamma from rainbow colors are present on their Classical Apple Computer logo

Old Apple Computer/s logo colors of rainbow 4 hbdi colors are there

Makes me wonder if Jobs employed the HBDI model in his company. Well what is the reason for people loving so much this rainbow colors combination. If we think for a second outside of HBDI's brainwashing ideology for what each color would stand for. Well it is simple is comes from our young years most of the people between age 2 and 50 years has been more or less exposed to the so colorful Kids Cartoons, which are all so colorfully painted. Since our very early age we've placed in us a love for colorfulness outlook (well again not all of us for example I prefer less colors, I'm sure there are plenty of people who don't like the heavy colors we see in almost everywhere around us).

The problem with this 4 colors use on purpose and all this unnatural color placing everywhere is that it is unnatural and not in good synergy with our surrounding natural environment. Therefore I personally think using a colorful color paintings on everywhere in both computer programs and the physical world plays us a bad joke and is one of the reasons so many people are on the virge to get crazy nowdays and many have already had already cracked out.

It is my firm believe more and more people should be educated on the harm of HBDI and the fact that, we're forced to 'live it' unwilfully every day by using even as "simple things" as computers and daily technology or buying food in the super market ,,,

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SWITCH OFF your Mobile Phone and TV at night to save energy!!!

Thursday, June 7th, 2012


We’re constantly being said to reduce energy consupmtion, they sell us new bulbs to save energy, new TVs with energy saving. The newer the computer equipment microwaves or whatever home electrical equipment we buy the more it is said to be saving energy.

So far so good it is true we can reduce energy consumption by producing gadgets which consume less. However there are also another approach to the “green problem” which we never are said about.

It is rather simply instead of saving energy on technology base, we can save energy on physical base. One simple thing to do to save energy with no need to spend money on latest advacement gadgets is to simply make it the old school way.

a -= Learn to switch off your lamps and home equipment whenever its not necessery

If you’re about to go to sleep, you can simply switch off the mobile and use a mechanical clock to wake you up on the morning, this way you have 3 benefits.

1; Less energy will be discharged by the mobile in the time you’re not awake, so you don’t need to charge so frequently the battery and therefore you will draw less energy from the Electrical network hence saving energy.

2; You will not be radiated with a bit less radiation produced by the Mobile phone in order to stay connected to the GSM local located cell.

Though the good this does will not be dramatical it for sure will be better for your health than if the mobile is switched on the whole night.

3; You will not be awakened in morning by some crazy person who just decided to call you early in the morning.
Often this morning unexpected and desired phone calls make you jump off the bed rapidly and hence giving a large dose of stress to your organizm.

-=- Of course switching off the mobile has some disadvantages if you can receive a crucial phone calls during all time of day or night you can’t afford to simply switch off the mobile, this is however not true for most people who work in an OFF-ICE.People working in offices can simply wake up at a scheduled time, get a shower do their morning hygiene and jump to a car or bus to the office so the need for having the mobile switched ON at night is not really needed.

Of course thinking in the same direction, it is logical that switching off the computer earlier when not needed, the wireless home router or the TV is another place from where a huge energy savings can be achieved.

If large amount of people re-learn their energy in-efficient habits to be more energy cautios a HUGE amounts of energy can be saved. This of course can have a positive impact on the monthly energy bills and hence can save you money in monthly expenses.

The TV is surely another big energy draining source, many people have the habit to sleep with a Television switched on. Besides this has a negative impact on the conscious since vast amounts of information are being stored and processed by the conscious and unconscious mind, also the lights emitted from the TV screen prevents the persons body to not have a pieceful rest.

Its rather stupid that companies are constantly ranting on how they improve their products to be energy friendly but they don’t invest even a penny to educate the masses that energy saving does not only depend on how good the technology is produced to save energy but also on how much the people are educated how to use the technology with energy saving in mind.Probably there are plenty of other ways a households can change their habits to save energy. I’ll be glad to hear some other suggestions ,,,

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Barcodes are dangerous for human freedom! Technology not trustable!

Monday, April 23rd, 2012

This post will be short as I'm starting to think long posts are mostly non-sense. Have you people all wondered of barcoding?
All world stores around the world have now barcoding. Barcode numbers regulations are being orchestrated by certain bodies, we people have no control over. Barcoding makes us dependent on technology as only technology can be used to read and store barcodes. It is technology that issues the barcodes. We have come to a point, where we humans trust more technology than our physical fellows. Trusting technology more than the close people to us is very dangerous. What if technology is not working as we expect it to?
What if there are hidden ways to control technology that we're not aware of?

Technology concepts are getting more and more crazy and abstract.
Thinks about the virtualization for a while. Virtualuzation is being praised loudly these days and everyone is turnning to it thinking it is cheap and realiable? The facts I've seen and the little of experience I had with it were way less than convicable.
Who came with this stupid idea, oh yes I remember IBM came with this insane idea some about 40 years ago … We had sanity for a while not massively adopting IBM's virtualization bulk ideas and now people got crazy again to use a number of virtualization technologies.
If you think for a while Virtualization is unreality (unexistence) of matter over another unreality. The programs that makes computers "runs" are not existent in practice, they only exist in some electricity form. Its just a sort of electric field if you think on it on a conceptual level …
As we trust all our lives nowdays on technology, how do we know this technological stored information is not altered by other fields, how we can be sure it always acts as we think it does and should? Was it tested for at least 40 years before adoption as any new advancement should be.
Well Of course not! Everything new is just placed in our society without too much thinking. Someone gives the money for production, someone else buys it and installs it and its ready to go. Or at least that's how the consumers thinks and we have become all consumers. This is a big LIE we're constantly being convinced in!
It is not ready to work, it is not tested and we don't know what the consequence of it will be!
Technology and Genetically Modified Food are not so different in this that they both can produce unexpected results in our lives. And they're already producing the bad fruits as you should have surely seen.
You can see more and more people are getting sick, more people go to doctor more people have to live daily with medication to live a miserable dishealthy I wouldn't say live but "poor" existence …
Next time they tell you new technology is good for you and will make your life better, Don't believe them! This is not necessery true.
Though todays technology can do you good, In my view the harm seriously exceeds the good.

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How to set up Qmail auto reply (Out of the Office), vacation message manually using .qmail message processing file

Tuesday, February 14th, 2012

Qmail Logo Auto reply message / how to setup qmail auto reply out of the office vacation message

I had to setup a QMAIL auto reply (Out of the Office) message on 5 email addresses and since I haven't done it for a long time it took me a couple 20 minutes to consult Qmail (Life With Qmail (great website!) documentation and read a couple of online forum threads until I finally remembered, how I used to be setting up a vacation message manually via qmail's .qmail file.

Of course Setting qmail auto reply can always be done via QmailAdmin or VQadmin ..Qmail Vpopmail web frontends however on many Qmail mail servers Qmailadmin or/and VQadmin is absent due to some reason or even on a big mail servers the server doesn't run Apache at all. Hence it is good to know how to set qmail vacation message directly via plain SSH terminal connection and this is why how this article got born.

So here is how I enable qmail auto reply "manually", through .qmail for my email address

1. Set a /var/vpopmail/domains/ file with the following content:

| /usr/bin/autorespond 86400 3 /home/vpopmail/domains/ /home/vpopmail/domains/

2. Create /home/vpopmail/domains/ directory

linux:~# mkdir -p /home/vpopmail/domains/

3. Create /home/vpopmail/domains/ file with auto reply message

First create the message file with touch command:

linux:~# touch /home/vpopmail/domains/

Then put with vim or mcedit etc. an auto-reply vacation message similar to the sample below:

Subject: We have received your message. Thank you!

Dear Customer, we thank you for the interest in our services.
A member of our team will reply promptly to your enquiry shortly.

4. Set proper permissions for vacation/message and .qmail files

/home/vpopmail/domains/ and /home/vpopmail/domains/ files has to be owned by user/group vpopmail:vchkpw, e.g.:

linux:~# chown -R vpopmail:vchkpw /home/vpopmail/domains/
linux:~# chown vpopmail:vchkpw /home/vpopmail/domains/

If you are a qmail administration with the requirement to create auto reply message for employees going on a holiday often (in a middle sized company office), setting up the out of the office auto reply manually one by one is a time consuming, annoying task and "crazy" task. Therefore some time ago while still I was employed in a Bulgarian mid-sized company called Design.BG, I've written a tiny shell script which creates qmail email users vacation messages by passing few arguments.

Here is my shell script
Note that this script might have a lot of bugs and is not much tested, so read it carefully and test it before you put it for daily use 😉
Happy Hacking! 😉

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Abe’s Amazing Adventure, A Dangerous Dave 2 like GNU Linux / FreeBSD Arcade Game substitute

Wednesday, December 14th, 2011

Abe's Amazing Adventure Game menu screenshot, A Dangerous Dave like Linux arcade game
While looking over the installable packages in System -> Administration -> Software Center on my my Debian powered notebook, I’ve accidently rolled over a game called Abe’s Amazing Adventure , as a big oldschool arcade game fan, I’ve immediately clicked on Install being impatient to see the overall game atmosphere and gameplay as well as storyline.

Abe’s Amazing Adventure is available under the debian package name abe and can be installed by issuing:

debian:~# apt-get install abe I was pleasently surprised to find out the gameplay and the overall game feels like the golden classical arcade game Dangerous Dave

For youngsters who never played the amazing absolute killing arcade ! as well as for people who feel nostalgic about Dangerous Dave 2 here is a nice gameplay screenshot:

Dangerous Dave 2 screenshot

Here is also a screenshot of Abe’s Amazing Adventure gameplay:

Abes Amazing Adventure Dangerous Dave like Linux / BSD Arcade Game like screenshot

You can see the great resemblense between the two games even by the screenshot; In both games you have to collect keys to open doors and diamonds which gives you points. Of course there are some differences as you can see Abe’s Amazing Adventure ‘s graphics has some additional items like Baloons with which your main character can fly over distances (for a limited time). There is also more diversity in the enemy types you face on the road to unlock the different doors. The game has also a red stars which while taken saves the game so if you quit the game on next game load up starting the game automatically starts you from the last save point.

Abes Amazing Adventure Star gameplay Screenshot on Debian

The ( 6 ) baloons seen in the screenshot on the left upper corner can be used occasionally to fly some distance by pressing Enter .
There are health recovery kits one can take to recover, some health damaged by hitting obstacles on the way.
The game story is short but entertaining, just like the general game feel:

Abes amazing adventure game storyThe game music is relaxing and more or less in the spirit of arcade games, the keyboard interactivety is pretty good as well.One thing I see can be improved to make the game better are the graphics, they’re a bit childish and too cubical, where sometimes some more general characters and obstacles animation will give the game a better look. Anyways for the year 2003 and for a free software arcade the game is not bad. For children and growing kids the game is just perfect, even for big kids like me its good to spend an hour of jump and run fun 😉

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How to solve “IPv6 addrconf: prefix with wrong length 48”

Friday, December 9th, 2011

While reading some log files on one of the co-located servers at , I’ve noticed dmesg log was filling in with tons of junk messages like:

[4288245.609762] IPv6 addrconf: prefix with wrong length 48
[4288445.984153] IPv6 addrconf: prefix with wrong length 48
[4288646.296110] IPv6 addrconf: prefix with wrong length 48
[4288846.609119] IPv6 addrconf: prefix with wrong length 48
[4289046.922604] IPv6 addrconf: prefix with wrong length 48
[4289247.267273] IPv6 addrconf: prefix with wrong length 48
[4289447.545800] IPv6 addrconf: prefix with wrong length 48
[4289647.857789] IPv6 addrconf: prefix with wrong length 48
[4289848.169308] IPv6 addrconf: prefix with wrong length 48
[4290048.595104] IPv6 addrconf: prefix with wrong length 48
[4290248.808497] IPv6 addrconf: prefix with wrong length 48
[4290449.103503] IPv6 addrconf: prefix with wrong length 48
[4290649.418747] IPv6 addrconf: prefix with wrong length 48
[4290849.742731] IPv6 addrconf: prefix with wrong length 48

After checking the message to make sure it would not suddeny lead to server hang ups I figured out the message is not dangerous but just an annoying warning that some other (routing) host on the same network as mine is advertising something using IPv6, that doesn’t fit with my IPv6 server config.
Actually the server doesn’t use the IPv6 configuration at all, and the assigned configuration is just some kind of auto set IPv6 IP address.
The server, where this message appeared is powered by 64 bit Debian GNU / Linux Squeeze

To resolve the annoying message, 5 of the kernel sysctl settings needs to be modified with cmds:

debian:~# sysctl net.ipv6.conf.all.accept_ra=0
debian:~# sysctl net.ipv6.conf.all.autoconf=0
debian:~# sysctl net.ipv6.conf.lo.autoconf=0
debian:~# sysctl net.ipv6.conf.eth0.autoconf=0
debian:~# sysctl net.ipv6.conf.eth1.autoconf=0

Furthermore to prevent the IPv6 addrconf: prefix with wrong length 48 to re-appear after future server reboots / boots the two sysctl values of course needs to be included in /etc/sysctl.conf e.g.:

debian:~# echo 'net.ipv6.conf.all.accept_ra = 0' >> /etc/sysctl.conf
debian:~# echo 'net.ipv6.conf.all.autoconf = 0' >> /etc/sysctl.conf
echo 'net.ipv6.conf.lo.autoconf = 0' >> /etc/sysctl.conf
echo 'net.ipv6.conf.eth0.autoconf = 0' >> /etc/sysctl.conf
echo 'net.ipv6.conf.eth1.autoconf = 0' >> /etc/sysctl.conf

My server has 2 etherhet interfaces, eth0 and eth1 that’s the reason I had to set up autoconf kernel the two vars net.ipv6.conf.eth0.autoconf and net.ipv6.conf.eth1.autoconf , for more interfaces more kernel vars (eth2, eth3) etc. needs to be set to “0”

I’ve seen posts online of people complaining about a similar errors to IPv6 addrconf: prefix with wrong length 48, like:

IPv6 addrconf: prefix with wrong length 96
IPv6 addrconf: prefix with wrong length 128

The solution to this messages is also done by setting the above described sysctl kernel vars. Setting the vars will suppress the messages which by the way with time could take up A LOT of disk space and fills /var/log/dmesg with this useless message, hence applying the “fix” is a must 😉

Another thing, I’ve noticed while I was researching about the error and the respective fix is that people on other deb based distributions like Ubuntu as well as on Fedora GNU / Linux had also experienced the issue.

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How to convert html pages to text in console / terminal on GNU / Linux and FreeBSD

Thursday, December 8th, 2011

HTML to Plain Text Convertion on GNU / Linux and FreeBSD

I’m realizing the more I’m converting to a fully functional GUI user, the less I’m doing coding or any interesting stuff…
I remembered of the old glorious times, when I was full time console user and got a memory on a nifty trick I was so used to back in the day.
Back then I was quite often writing shell scripts which were fetching (html) webpages and converting the html content into a plain TEXT (TXT) files

In order to fetch a page back in the days I used lynx(a very simple UNIX text browser, which by the way lacks support for any CSS or Javascipt) in combination with html2text – (an advanced HTML-to-text converter).

Let’s say I wanted to fetch a my personal home page, I did that via the command:

$ lynx -source | html2text > pcfreak_page.txt

The content from got spit by lynx as an html source and passed html2pdf wchich saves it in plain text file pcfreak_page.txt
The bit more advanced elinks – (lynx-like alternative character mode WWW browser) provides better support for HTML and even some CSS and Javascript so to properly save the content of many pages in plain html file its better to use it instead of lynx, the way to produce .txt using elinks files is identical, e.g.:

$ elinks -source | html2text > pcfreak_blog_page.txt

By the way back in the days I was used more to links , than the superior elinks , nowdays I have both of the text browsers installed and testing to fetch an html like in the upper example and pipe to html2text produced garbaged output.

Here is the time to tell its not even necessery to have a text browser installed in order to fetch a webpage and convert it to a plain text TXT!. wget file downloading tools supports source dump as well, for all those who did not (yet) tried it and want to test it:

$ wget -qO- | html2text Anyways of course, some pages convertion of text inside HTML tags would not properly get saved with neither lynx or elinks cause some texts might be embedded in some elinks or lynx unsupported CSS or JavaScript. In those cases the GUI browser is useful. You can use any browser like Firefox, Epiphany or Opera ‘s File -> Save As (Text Files) embedded functionality, below is a screenshot showing an html page which I’m about to save as a plain Text File in Mozilla Firefox:

Firefox iceWeasel Opera etc. save html webpage as plain text on GNU / Linux, FreeBSD

Besides being handy in conjunction with text browsers, html2text is also handy for converting .html pages already existing on the computer’s hard drive to a plain (.TXT) text format.
One might wonder, why would ever one would like to do that?? Well I personally prefer reading plain text documents instead of htmls 😉
Converting an html files already existing on hard drive with html2text is done with cmd:

$ html2text index.html >index.txt

To convert a whole directory full of .html (documentation) or whatever files to plain text .TXT , cd the directory with HTMLs and issue the one liner bash loop command:

$ cd html/
html$ for i in $(echo *.html); do html2text $i > $(echo $i | sed -e 's#.html#.txt#g'); done

Now lay off your back and enjoy reading the dox like in the good old hacker days when .TXT files were fashionable 😉

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