URLs and Linking to Resources

• Specifies the location of a resource (HTML document, file, program, or whatever)
• Has the following syntax (in general):
  service://host.domain[:port]/path/filename
  • service can be http (for hypertext), ftp, gopher, wais, telnet, news, or mailto.
  • host.domain is the Internet domain address for the host.
  • port is an optional port number, if the service is not at the default port.
  • path is a directory path name to get to the file.
  • filename is the name of the file to be obtained, which can be hypertext, plain text, data, graphics, sound, a movie clip, or a program.
  • Parts of the above can be left out.
  • Syntax varies for special services (e.g. news and mailto).
• Can be absolute (fully specified), or a reference relative to the current document.
• Some examples:
  • Hypertext: http://www.cs.umanitoba.ca/~gedetil/,
    http://c.gp.cs.cmu.edu:5103/prog/webster
  • FTP: ftp://ftp.muug.mb.ca/pub/muuglines/ps/muug9409.ps
  • News: news:comp.infosystems.www.announce
  • E-mail: mailto:gedetil@cs.umanitoba.ca