Understand the URL
Author: Jiang Xuezhe (netsail0@163.net)
Reference: Reference Daquan HTML (Third Edition) Tsinghua University Press [United States] Thomas A. Powell Yang Zhenghua Ge Rankan Li Jinbo Chen Yuxiang translation
Tint Jiang Computer Program Group (chulsoft.xiloo.com) Copyright, reprint, please explain it. -------------------------------------------------- --------------- suddenly remembered the "Empire Times". When she played her for the first time, the magnificent picture of the game gave me a huge shock. I am deeply fascinated by her. I carefully observe every detail in the game. "Star Battle" is that I like it later, I have put all the energy in the "Emperor Times". In all games I have played, I have an irreplaceable position in the Imperial Times. That is the only game for me. After that, I have never had that feelings. I specially bought genuine "Emperor Times" from South Korea. Write this article before I found the feeling of the year and played a "Empire Times". The topic is far away.
http://www.google.com/search?q=cs flash 十佳&ie=utf-8&oE=utf-8&hl=zh-cn&btng=google搜% E7% B4% A2 & lr =
Can you understand the URL above? I think many people don't understand, I am also. The above URL is the result after the keyword "CS Flash Ten" search in Google.
The Standard of the URL is a Uniform Resource Locator. My English is not ridicpeled, so I can only check the mountainee. Uniform "Unified", Resource "Resource", Locator "Locator". The basic URL structure is as follows:
Agreement: // URL / Directory / File Name /
http://www.microsoft.com/
The above is Microsoft's URL. The WWW is "machine name". Microsoft is a "domain name" and COM's type.
COM -----------> Commercial entity or personal NET -----------> Network or network provider Org -----------> Non-profit Sexual organization edu -----------> University GOV -----------> Government agency MIL -----------> Military institutions
Some of the domains outside the United States are somewhat complicated. A FQDN including country code (full qualified domain name) is as follows:
Agreement: // Machine name. Domain name. Country code /
Http://www.sina.com.cn
The CN represents China. In addition, JP represents Japan, KR represents South Korea, CA represents Canada, MX represents Mexico.
The real address of the server on the Internet is an IP address instead of a symbol address. The IP address consists of four numbers. Each number is between 0 and 255, and the numbers are separated by a point number. But using symbolics We can easily access the Internet server. After all, a large string number is not conducive to memory. E.g
http://202.108.37.36
May correspond to
Http://www.sina.com.cn
The symbol name must be parsed to an IP address before using the URL positioning server. There are special service providers to provide this service. Domain Name Service (DNS: Domain Name Service). The user entered in the browser address bar will automatically be parsed by the DNS server to an IP address.
For network operations, domain name format and domain name findings are critical. If there is no DNS server, it is impossible to access the web server. For more information on machine names and domain names, please visit the following website (if your English is ok): http://rs.internic.net/http: //www.iana.org/http: // Www.gtld-mou.org/
Domain name is not case sensitive.
The protocol is the structured communication of the computer, thereby providing a particular resource service. For example, a protocol that supports Web is called hypertext transport protocol (HTTP). When the user clicks on a hyperlink of the web document, the browser uses the HTTP protocol to establish a connection with the web server, and then obtain the required document.
HTTP represents Hypertext Transfer Protocol.
In addition to HTTP, there are other agreements.
File -----------------------------------> Make the file that can access the local file system via the hyperlink . File Transfer Protocol (FTP: File Transfer Protocol) -> Make you access to files on the remote system through hyperlinks. Gopher ---------------------------------> makes it access to the Gopher server through hyperlinks. Simple Mail Transfer Protocol (SMTP: Simple Message Transfer Protocol) ---> The mail protocol used on the Internet. Post Office Agreement (POP: Post Office Protocol) ---> A protocol used to receive mail. Network News Transfer Protocol (NNTP: NetWork News Transfer Protocol) -----> Make you can access the USENET news article through hyperlinks. News -------------------------------------> makes it accessible to the USEnet news group through hyperlinks. Telnet ----------------------------------> The standard protocol used for remote connection services.
FTP and Telnet are privileges that require user authentication. Authentication service guarantees, can only be accessed by authorized users. So the protocol needs to be used as a username and password. The username and password must be placed before the server:
FTP: // Username: password@ftp.downmovie.com
The password is prior, may not be given in the URL, then the form will become:
FTP: //Username@ftp.downmovie.com
Although rare, sometimes you need to specify port numbers in the URL, each protocol has a default port number, for example, the default port number of the HTTP protocol is 80. Server administrators can reconfigure the server so that it can handle requests for the appropriate protocol on non-default ports. It is best not to change the default port number because it may make users confuse.
The URL cannot display some special symbols, and this time you use coding. The format encoded is: a percentage, followed by the ASCII code value of the corresponding character. For example, the encoding value of "@" is "% 40".
Some simple notes are available when using a directory in some systems. For example, UNIX-based web servers may have a number of directories, each of which is owned by a specific user. This time does not need to write the full path of the user's root directory. The user directory can be short-written as "~" (wavy line). The back user account is then a slash. The following directory and file names are relative to the user's home directory.
http://www.unix.com/~root/
The HTTP URL can also access and execute the server program. Server-side programs are often referred to as a public gateway interface (CGI CommON Gateway Interface) program. It uses an interface standard. This standard describes how the program receives and transmits data. The formula is as follows: Agreement: // URL / Directory / File? Parameters
http://www.google.com/search?q=cs flash 十佳&ie=utf-8&oE=utf-8&hl=zh-cn&btng=google搜% E7% B4% A2 & lr =
At this time, I returned to this URL who saw the beginning of the article.
Search in front of the question mark is the file.
Q is the first parameter, which is equal to "CS FLASH % E5% 8D% 81% E4% BD% B3". The second parameter is IE, namely: & IE = UTF-8 third parameter is OE, & OE = UTF-8 fifth parameters: & hl = zh-cn sixth parameter: & btng = Google% E6% 90% 9C % E7% B4% A2 last parameter: & lr =
"&" Means that it is a parameter behind. Now, can you understand the complex URL above?
