|Your Date, Time, and Time Zone more
Read from the clock and data in your computer.
|Your Screen Resolution more
|Your Screen Color Depth more
|Your Browser Plugins and their File Names more
The items below are sent in your HTTP headers and
received by my server.
Every web page you go to gets this info, and there is nothing you can do about it.
|Your Computer, OS, and Browser more
|Your IP Address more
or the IP address of your outermost firewall.
|Your Host Name more
or the Host Name of your outermost firewall.
Warning: gethostbyaddr(): Address is not a valid IPv4 or IPv6 address in /home/beeman/www/www/about_you/index.php on line 434
|Your port # more
On your computer or outermost firewall.
|Page Requested more
The page your browser requested
The URL of the page with the link that sent you here.
|Request Method more
The HTTP Method Your Browser Used for this Request.
|Query String more
Everything after the question mark in the page URL.
|Encoding Methods more
Encoded data types your browser says it will accept.
Languages you will accept with preference indicated.
|HTTP Data Accepted more
The kinds of data encoding that you will accept.
|HTTP Character Sets Accepted more
The kinds of character encoding that you will accept.
|Your Social Security Number
Relax: its a joke.
One of my evil friends suggested I should put this here.
Shame on you Mr. Stockdale!
Digits masked by Xs for privacy
The date is represented in standard ISO format: Year-month-day. Get used to it.
The Time from your computer clock is represented in 24 hour format.
Your Time Zone from UT in minutes (East +, West -).
Like your IP address, your time and time zone can be used to find your approximate physical location. This is especially true if you live in one of those areas that is offset by a fraction of an hour from UT.
Plug-ins are numbered starting from zero and that's how I show them here. Why count from zero? Its like counting birthdays. Your zeroth birthday is the day you are born. Your 1st birthday is when you are one year old, your 2nd birthday is when you are two years old...
Databases and services are available that identify the ranges of IP addresses used by each Internet Service Provider (ISP) and in which locations they are used. So any web site operator that really wanted to know where you are physically located could probably determine this within a few dozen kilometers. Doing this costs money, but not big money, so you should assume that anyone running a website who really wants to know your approximate physical location can discover this.
Both TCP and UDP have an additional pair of "port" numbers (destination and source),
which are 16-bit numbers (decimal values 0 through 65535) and are basically treated as
an extension of your IP address. Port numbers are assigned by the Internet Assigned
Numbers Authority (IANA) as follows:
0 - 1023: Well-known ports. Used for defined services. 1024 - 49151: Registered ports. Should be registered before being used. 49152 - 65535: Dynamic and/or private ports. No rules.Port 80, for example, is used on servers for incoming web page requests using HTTP. When you request a web page you send a request "to" port 80 on the server. You send this "from" a port on your computer which has a number at or above 49152. When the server returns the web page, it returns it "to" your IP address and the port number that you used for your request. The "from" port number in this reply is 80, since you used this in your original request.
When you request images or other info that may be on a page, each of these is requested "from" a different port number on your computer and returned to that port by the server. This allows you to request multiple items that make up a web page simultaneously from the same server without your computer (or the server) being confused. Normally, port numbers on your computer advance by one with each request until reaching 65535, at which point the next request will jump back to around 49152.
you will probably see the actual page here:
The "index.php" was appended to your request by my server because this is the default first page in a directory for UNIX-based web servers. For Windows-based servers the default first page is "default.html". If there is no default page, you will receive an index of all the documents in that directory, if permitted by the web server. Web sites that wish to hide the contents of directories will make sure that there is a default page in the directory, even if it is a blank page. That way nosy people can't list directories. Some web servers don't allow retrieval of indexes of folders, and some allow it to be configured by each web master.
The part of the URL which identifies the web site is case-insensitive. These two URLs are equivalent:
But the part after the web site may or may not be case-sensitive, depending on the server. My hosting company (ICDsoft) uses UNIX-based servers and so the following are NOT equivalent:
If you try to point your browser to the one with caps, you will get a "404" (page not found).
Since you probably didn't put a question mark in the URL when you requested this page, this will be blank. To see what would happen if you did, go to the address field in your browser and type (or copy and paste):
When you do this, and refresh the page, you should see "gandalf" as the query string.
This is often used as a trivial way to send data to web sites without the hassle of using the PUT or POST methods of HTTP. Yahoo's stock quotes work this way. I have placed a link below to get stock price quotes from Yahoo for Apple Computer (aapl), ibm (ibm) and Microsoft (msft) using their respective ticker symbols:
Click the link to see what happens. As you can see from the above, the query string for this request is:
Some characters, such as space and any other characters outside the range 33-127 (decimal), need to be encoded specially. This is done because URLs are limited to certain characters, and characters that are not allowed are encoded as a "%" sign followed by two hexadecimal (base 16) digits indicating the character number. Space is ASCII character number 32, which is 20 in hexadecimal (two 16s and no ones) and so is encoded as "%20. This of course implies that the "%" character (ASCII 37) must itself be encoded as "%25", or else ambiguities will arise. For example, if you didn't always encode "%" signs, the characters "%20" would be the encoding of both "%20" and "% " (percent space). In actuality you would encode "% " as %25%20" and you would encode "%20" as %2520". When working with computers and data, ambiguities are deadly.
Query Strings can interact with caches. Many web pages are cached (stored locally) by your ISP. This is done to avoid continually retrieving popular but distant web sites over expensive long links. When you request such a page it is served from the ISPs cache, not from the site itself.
Sophisticated web sites have info in the HTTP headers of their site about when the site was last refreshed and when the next update is to be expected. These headers are very small compared to the size of the pages themselves. This allows the ISP to check these headers periodically so that they know when changes occur. This means that you almost always get an up-to-date page, despite caching. It also means that things like web-site hit counters are often not accurate, since many site views don't actually go to the site.
Obviously, web sites which depend on information from you, like Yahoo's stock quotes, cannot be cached. To do so reliably would require the ISP to have access to all of the databases and program logic on the site. This is almost never possible, as many of these items are proprietary. To allow for this, if the URL for a page contains a "?" (unless it is immediately followed by a "#") the request will bypass any caches in the path and go directly to the web site. This can be useful when you know that a site should have been updated and you keep getting an old copy. Just put a "?" at the end of the URL. Don't abuse this knowledge!
Sometimes there are multiple ways to encode something, and in that case a method for encoding preferences is used. Your first preference is the first item. Lower preferences are comma delimited and show order of preference with a "q" value (0 to .99). Highest "q" value is most preferred option. After the first item, the order of appearance is not important. Only the "q" values matter. For example, my browser shows the following preferrences:
gzip, deflate;q=1.0, identity;q=0.5, *;q=0
That means that gzip and deflate are preferred, identity is acceptable and everything else (asterisk) is not accepted.
"q" coding is also used for indicating other preferences, including for Language, Data Types, and Character Sets.
The list of languages and their codes is maintained by the Internet Assigned Numbers Authority at Iana Language Subtag Registry. Unfortunately, the names of the languages are the English names only. Thus to find Spanish you would look for "Spanish", rather than Espanol. Case (capitalization) is not significant. Thus ES, Es, eS, and es all refer to Spanish. IETF RFC3066 Tags for the Identification of Languages sets out the rules for usage.
After the language identifier there can be a national variant identifier. Thus English as spoken in the UK would be identified as en-gb (or unofficially as en-uk as per the TLD code for the UK) and as spoken in the United States would be en-us. The official list of Country names is kept by the International Standards Organization, English country names and code elements. The list of country names used as Internet suffixes is kept by IANA IANA ccTLD Database. Sometimes these are used for national sub-identifiers instead of the official ISO ones. An example would be en-uk, since the UK has two internet TLDs: uk and gb.
Some web pages have multiple languages available, and will give you the highest prioroity one in your list that they have available.
The top ones on my Safari browser (most preferred first) are:
|English: US variant
|Generic English: any version
|Spanish: Spanish variant
|Generic Spanish: any version
You did not see this. Your eyes are growing heavy. You will scroll up and remember nothing...