bcug internet workshop 2013-07-05 internet round table and ... · bcug internet workshop –...

BCUG Internet Workshop 2013-07-05Internet Round Table And Other Wanderings

By Gilbert Healton <[email protected]>

http://www.bcug.com/

Copyright 2013 by Gilbert Healton under Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported

BCUG Internet Workshop – Browser Notes of 20 Last updated 2013-Jul-14

DisclaimersInformation prepared for casual workshop on a quick effort basis and intended to supplement the presentation. Use at your own risk. Also some wording has been crunched down to fit the page/slides better.

BCUG is not a part of the college it happens to meet at.

http://www.bcug.com/

http://creativecommons.org/licenses/by-nc-sa/3.0/

http://creativecommons.org/licenses/by-nc-sa/3.0/us/

ContentsTable of Contents 1 Trademarks...................................................................................................................................................................................................................................2 2 Referenced Web Pages.................................................................................................................................................................................................................3

2.1 BCUG Workshop Notes.......................................................................................................................................................................................................3 2.2 Gilbert's Home Page.............................................................................................................................................................................................................3

3 Web Browser Security.................................................................................................................................................................................................................4 3.1 Notes....................................................................................................................................................................................................................................4 3.2 Know Thy Links (Also Applies To Most Incoming Email).................................................................................................................................................4 3.3 Browser Security Plug Ins....................................................................................................................................................................................................7

3.3.1 Available On Most Browsers........................................................................................................................................................................................7 3.3.2 Fire Fox Only (Mozilla based browsers)......................................................................................................................................................................8

3.4 Active-X Safety (also Java, Flash, Silver Light, ...).............................................................................................................................................................9 4 Unicode and UTF-8.....................................................................................................................................................................................................................9

4.1 Character Sets.......................................................................................................................................................................................................................9 4.2 ASCII Character Set...........................................................................................................................................................................................................10

4.2.1 Original Ascii..............................................................................................................................................................................................................10 4.2.2 Ascii Is Not Enough....................................................................................................................................................................................................12 4.2.3 Unicode and The Universal Character Set.................................................................................................................................................................13 HTML Is Unicode...............................................................................................................................................................................................................16

5 Other subjects touched...............................................................................................................................................................................................................17 5.1 E-Mail................................................................................................................................................................................................................................17 5.2 Google Maps......................................................................................................................................................................................................................19 5.3 Google Earth......................................................................................................................................................................................................................20

1 TrademarksThis author has attempted to list trademarks used within this document. The names of actual companies and products mentioned herein may be the trademarks of their respective owners.

BCUG is from the Brookdale Computer Users Group that meets in Middletown, New Jersey. Visit www.bcug.com.

Google®, Google Maps®, Google Mail®, Google Docs®, Google Drive®, and Google Earth® are registered trademark of Google Inc.


Microsoft®, Windows®, Hot Mail®, and Outlook® are registered trademarks of Microsoft Corporation. Bing, and/or other Microsoft products and services referenced herein may also be either trademarks or registered trademarks of Microsoft in the United States and/or other countries.

Mac® and Mac OS® are trademarks of Apple Inc., registered in the U.S. and other countries.

UNIX® is a registered trademark of The Open Group.

Wikipedia ® is a registered trademark of the not-for-profit Wikimedia Foundation.

Linux® is the registered trademark of Linus Torvalds.

GNU® is a registered trademark of the Free Software Foundation.

XKCD is a web comic whose work is licensed under a Creative Commons Attribution-NonCommercial 2.5 License.

Yahoo!® is a registered trademark of Yahoo! Inc.

This work is licensed under a Creative Commons Attribution-NonCommercial 2.5 License.

2 Referenced Web Pages

2.1 BCUG Workshop NotesNotes from prior Internet Workshops can be found on the BCUG web site:>> [ Meetings ] >> Workshop News/Notes >> “Internet Workshop” <<

http://www.bcug.com/workshops.htm

2.2 Gilbert's Home PageA lot of material was pulled off this author's home page found at:


http://www.bcug.com/workshops.htm

http://www.exit109.com/~ghealton/Dreaming of moving to www.heatlon.netThe most frequent material was pulled from:

• Yellow navigation are on the left:

• Date and Time / Current Time: material on finding current time of day.

• http://nist.time.gov/ requires Java, Active-X, etc. See following security section.

• Date And Time information near bottom of page in main white area.

Ways to find Gilbert's pages:

• Search for “Gilbert Healton” “Home Page” (quotes important)

• Search for “Original Mad Programmer”

3 Web Browser Security

3.1 Notes• Rather than .com, .net, etc., this document uses .invalid and .sample for the top level domains I


http://nist.time.gov/

http://www.exit109.com/~ghealton/

don't want you to go to, even by accident. These names are actually reserved just for this purpose.

3.2 Know Thy Links (Also Applies To Most Incoming Email)While this started off as an E-mail security question it applies even better to web pages. Most E-mail is either HTML (e.g., web pages delivered by E-mail clients rather than web browsers) or “Rich Text” (e.g., word processing documents delivered by E-mail).Whenever you over over a link the status, usually in the lower left side of the window, shows where the web page is truly going regardless of what you see on the main screen. What you see on the screen need not be what you get when you click because the way HTML “Anchor” tags work. Look inside the raw HTML and you can see.


What you see: City Bank ServicesWhan you don't see unless you look: magic HTML “Anchor tag” < . . . > controlling the link:

<A href=”http://www.rip-you-off.invalid/CityBankService”>City Bank Services</A>

• Much clutter can be found in <A> tags. title= to name a popular one. You may have to wade a lot to isolate the href.

• Any “=” codes in quotes or visible text may be special. =20 is a space. Other values exist and the line endings may be strange so carefully watch your < > and open/close quotes. Especially from pages wanting to hide it's evil.

• In the following section on Unicode/UTF-8, look up “hex 20” in the ASCII table to see this work.

• Hyper-text reference show where you will really go.

• Domain name: what is really important is the actual domain name. Last two period (.) separated names.

• Web site owners must register as their own this part of the name. They may lie to registers but they must sill register.

• BCUG.NET. healton.net. Case is not important. Be fussy on what you check here. barc1ays.com is not Barclays.

• The stuff after the / following the domain name is up to the spammer.

• Even the “www”, or whatever, to the left of the domain name is under control of the domain owners. barclays.rip-you-off.invalid is not Barclay's.


<AStarts clickableLink. “>” ends.

href=". . ."Deceivers must point to

A site they control.

VisibleThis is what you see

...href continueddeceivers can put

anything they like here

slot:

slot:

Every web browser and every e-mail agent provides some way to view the raw HTML, usually called a “source” of some type.

• IE 8 : >> View >> Source <<

• Fire Fox: >> Tools >> Web Developer >> Page Source <<

• Thunderbird: >> View >> Message Source <<

3.3 Browser Security Plug InsAll browsers have some way of adding more features to it. The big browsers have huge libraries of plug ins. Your browser may call it something else (Fire Fox has Add Ons), but a plug in by any other name runs just as sweet.

3.3.1 Available On Most BrowsersWOT: Web Of Trust

www.mywot.com/ rates web sites around the world on several areas... Trust, child safety, and more.

• Many web pages you go to will start showing WOT ratings for the links on the page, or a symbol showing a lack of ratings.

• Tries to block bad sites unless you override.• As anyone registering with WOT can rate websites you must use the

rating carefully.


http://www.mywot.com/

• Some good sites may show poorly.• Some bad sites may show good, especially of owner works at it.• Just one point in many to protect yourself.

3.3.2 Fire Fox Only (Mozilla based browsers)No Script http://noscript.net/ controls which websites can execute potentially

dangerous programs in your web browser. While all evil sites must do this so do many good web sites.

• You get a bar at the bottom of each web page No Script is alarming on. The bar's right side allows you to train No Script on what are your good web sites.

• You can permanently trust your good sites, temporarily trust likely sites, or never trust doubtful sites.

• Search using Google, Bing, sites you don't know to see what the ratings are. Example: search (with quotes) “Google.com ratings”.

• If you go to a web site and little, or even nothing, is working look at the No Script bar.

• It's a bit annoying to train it at first, but No Script is good.• Many sites, such as BCUG, use scripts to get nifty menus.• In my mind proper sites will work without scripts. By this there are a


http://noscript.net/

lot of “improper” sites out there run by honest people.• Sometimes parts of a web page, such as videos, will show blocking

icons. Right clicking that item shows you a list specific to the item.

3.4 Active-X Safety (also Java, Flash, Silver Light, ...)Many web sites want, even need, to deliver programs to you in order to deliver services to you. All malware must use these to infect or abuse your computer. The trouble is good sites need this to.Java, Flash, Silver Light, are all browser features that allow such programs to be delivered to your browser. You may get a “do you want this” box. You may not. If you use Fire Fox the “No Script” Add On along makes it worthwhile to switch to Fire Fox.

4 Unicode and UTF-8

4.1 Character SetsWay back when computers were big and expensive there were two major character sets out in the wilds along with many small fry These are used to map numbers in computers to characters you see on screens, printers, keyboards, etc.

• EBCDIC – Extended Binary Coded Decimal Interchange Code from IBM. As IBM dominated early computing this was quite popular.


• ASCII – American Standard Codes for Information Interchange.. what just about everyone else in the world used, whether they liked English or not.

• Others – other manufacturers had their proprietary codes. The dominance of PCs made ASCII by far the most popular code. EBCDIC is still around but is mostly limited to IBM mainframes, and compatibles. Most others have died.

4.2 ASCII Character Set

4.2.1 Original AsciiA table showing Ascii codes follows. You will see each character has a number associated with it. Just to be sure the number is shown three different ways. What is important here is the stuff in red and the left-most number to the left of the red character.


The left column is control codes used to control things. 0 is “null” (nothing, ignore this). 7 is “bell” (bing!), 13 is Carriage Return (the Enter key). Most of the others get so esoteric we will not touch them.The three right columns show what you see on your PC keyboards.

http://www.asciitable.com/

Ascii codes always fit in the bottom seven bits of an eight-bit byte. The top byte is always off.

• Ascii files are made by programs such as “Notepad”. No fonts. No point sizes, No bold. Only pure characters, end of line, tabs, and a few other basics.


http://www.asciitable.com/

• Files for programs, such as configuration files and most “source programs” programmers write are straight Ascii files. Clean and simple without clutter. To avoid the pain of Notepad serious Ascii users tend to use powerful “text editors” like vi and EMACS. Normal people may use Notepad++.

4.2.2 Ascii Is Not Enough

• Ever want a ¢ cent sign? Basic Ascii does not have this, and other common characters.

• The first trick was to fill Ascii 128 and on with additional special characters, such as cent sign. The IBM PC style of Extended Ascii is on the right.

• Other languages also took over 128 to 254 for non-English characters. French had one way. Spanish another. Cyrillic, Arabic, assorted European, Asian, and more.

Extended Ascii

(these are NOT Unicode code point values... Unicode is different)

• The globalization of computers and the Internet drove the need for one computer to write many different languages. The use of 8-bit characters was out and bigger character sets became “in”.


4.2.3 Unicode and The Universal Character Set• Two different groups started developing ways of coding all characters for all languages into

computers. The two have effectively merged today and Unicode is the dominant name.

• Unicode does not just add more numbers later on... it

• Breaks the bonds of being designed without the messy problem of stuffing numbers into computers. Unicode numbers are abstract (well, all right, there was some thought).

• Was designed for a huge number of swaths of numbers The range of numbers is divided down into planes, blocks, down to individual code points.

• UTF-8: stuffs numbers into computers using various character encodings. Unicode Transformation Format... 8-bit being the most popular.

• UTF-8 is interesting: code points (characters) use a variable number of bytes.

• Plain old Ascii, including Ascii control codes, use one-byte per code point in the C0 block.

• The higher the encoding number the more bytes needed... but there are strange rules about this I'm not going into here (when I said I've written programs to work UTF-8 one person responded “I'm sorry”).


I don't see how; the C0 block is right there at the beginning.

http://xkcd.com/1209/(Explain XKCD Jokes)

c

https://en.wikipedia.org/wiki/Character_encoding

https://en.wikipedia.org/wiki/Character_encoding

http://en.wikipedia.org/wiki/Unicode

http://xkcd.com/1209/

http://www.explainxkcd.com/wiki/index.php?title=1209

• Can cope with right-to-left as well as our Right-to-left English. Even mixing up directions on the same paragraph. This can make browser rendering complex.

• The fonts get kind of funny here.... before your computer can use UTF-8 your computer must have the fonts for the parts you want to use.

• Most browsers and word processors come with the popular fonts... we will revisit this soon.

• For sound technical reasons deep technical people use hexadecimal numbers when referring to Unicode numbers.

• Like regular numbers but with A to F following 0 to 9. Hexadecimal numbers, or just “hex” if you will. Consider it a curse if you want.

• Like counting with six fingers and two thumbs on each hand.

• Normally you don't have to do math, count, or such, just read and maybe copy and at worse sort.

Hexadecimal Numbers


• Extracts from some typical blocks follows. These are direct copies of the official Unicode tables. The “U+xxxx” is the official Unicode representation of the code point.

code points character UTF-8(hex.) Official Unicode Name

U+0000 00 <control>U+003D = 3d EQUALS SIGNU+003E > 3e GREATER-THAN SIGNU+003F ? 3f QUESTION MARKU+0040 @ 40 COMMERCIAL ATU+0041 A 41 LATIN CAPITAL LETTER AU+0042 B 42 LATIN CAPITAL LETTER BU+0043 C 43 LATIN CAPITAL LETTER CU+00A1 ¡ c2 a1 INVERTED EXCLAMATION MARKU+00A2 ¢ c2 a2 CENT SIGNU+00A3 £ c2 a3 POUND SIGNU+00A4 ¤ c2 a4 CURRENCY SIGNU+00A5 ¥ c2 a5 YEN SIGNU+2665 ♥ e2 99 a5 BLACK HEART SUITU+2666 ♦ e2 99 a6 BLACK DIAMOND SUITU+2667 ♧ e2 99 a7 WHITE CLUB SUITU+2668 ♨ e2 99 a8 HOT SPRINGSU+2669 ♩ e2 99 a9 QUARTER NOTEU+266A ♪ e2 99 aa EIGHTH NOTE

• A interesting set that most computers support most characters in is U+2600 … U+26FF: Miscellaneous Symbols.


Note: the bigger thecode point number

the more UTF-8 bytesthere are.

• http://www.utf8-chartable.de/unicode-utf8-table.pl?start=9728

• This has musical notes, odd hearts, starts, and lots of other things to decorate your messages in text and one the web with.

♫ ♪ ♪ ♬ Note This ♪ ♪ ♫ ♬• Not everything in this code set works well... you will have to experiment. Just because you see

it doesn't guarantee others will also see it. The notes seem pretty good though.

• If you forget this link or name search for, and the quotes are important:"UTF-8" musical notes

• This is missing clefs and other musical notation. And some of the other stuff it has does not port well across the web.

• Once a letter occurs in a block for one language it is not repeated in the block for any other language. Anything that looks like a duplicate isn't, if you dig deep enough.

• Languages with, even if unofficial Unicode support using “user defined” blocks, support Elvish from Tolken's Lord Of The Rings, Klingon from Star Trek, and many more artificial languages.

HTML Is Unicode

• HTML is usually Unicode, keeping to the 7-bit ASCII code set with yet a different way to encode special characters beyond plain old ASCII.

• Characters not in Ascii us special “&” “entity” codes:


http://www.utf8-chartable.de/unicode-utf8-table.pl?start=9728

< Less than < <> Greater than > >& ampersand & &¢ cent ¢ ¢£ pound £ £

• These & codes use decimal numbers like regular people do. Go back to the Ascii chart and look at the less than and greater than.

• Other encodings for HTML are possible, but in practice not used much for English.

• Formatting and control commands are enclosed in special “<” ... “>” angle brackets to make “tags”.

• The <A ...> anchor tag in the prior Know Thy Links section is an example.

• When a web browser connects to a web server the two negotiate which language and encoding is going to be used. Or at least they can be set up to do so. Single language web sites don't do much here.

5 Other subjects touched

5.1 E-Mail• When you get Internet services from the major telephone companies (“telco”s)


they give you easy to use E-mail addresses for free.• It is a bad idea to use these for if you move or switch services you need to

suddenly and completely get everyone to switch E-mail addresses.• Go to one of the providers of free E-mail and open a long term account there.

Several of them actually.• One primary account to give to your inner circle.• A secondary account, on a different provider, to give to subscription lists

and other places that may spam you.• Google, Hotmail, Yahoo... there are so many providers of free E-mail.

• Sign up with some, such as Google, and you also get the other other services (Google Docs, Google Drive, My Maps, …).

• Each free account requires a base E-mail address to contact you at. If nothing else when you forget your password or have other troubles that E-mail can help you recover from.

• Your first account can use your ISP provider as the E-mail. A good choice. Change if you switch ISPs.

• Your second account can use your primary account, or your ISP. You


choose.• Many ISP accounts can be set to forward incoming E-mail to some

account so you don't have to keep reading all those accounts.• Be sure to avoid infinite E-mail forwarding loops.• Be sure to cancel forwarding on the ISP account if you need the E-

mail delivered there to recover a password on another account.• Google mail does not pay attention to any periods/dots in your name.

[email protected] is the same as perlspeaker is the same as p.e.r.l.s.p.e.a.k.e.r.

5.2 Google Maps• Virtual driving.• Street view.

• New navigation: • press further down the road to jump.• A square on a building gives more information if you click.

• Layers:


• Traffic layer. But also compare with the more pessimistic www.sigalert.com to average them and catch major problems one or the other misses.

• 3D Buildings... building owners can upload 3D models of their buildings. • In dense places the street level can look really strange as adjacent models

clash with each other.

5.3 Google Earth• Much more details on earth... less focus on streets.• Application you must install locally.• Microsoft Windows only... I think.


http://www.sigalert.com/

bcug internet workshop 2013-07-05 internet round table and ... · bcug internet workshop –...

Documents