Normally, each request for a World Wide Web page which comes in to a server
stands on its own. While the server will probably know which machine a
request comes from, it may not know if the next request comes from the same
browser or even from the same user on that machine.
MiniVend keeps track of who is ordering by one of two means:
- Cookies
-
MiniVend can issue cookies that contain the user session
ID. If the user returns the cookie, then they can be
presented pages without accompanying session information.
- URL re-writing
-
If the user doesn't want to use cookies for whatever reason, MiniVend will include in the
URL a
session id, which is a random piece of text which is different for each customer
browsing the catalog.
MiniVend will automatically do the right thing depending on whether the
user gives back a cookie.
Pages in the catalog served by MiniVend running as a cgi-bin program generate a special
URL for every link. Here is an example of such a
URL:
http://www.minivend.com/cgi-bin/simple/browse1?id=WehUkATn&;pc=122&ar=99-102
An explanation of each part:
- www.minivend.com
-
Internet address of the server hosting the MiniVend catalog.
- cgi-bin
-
Informs server that the requested page will be generated by a program. This can be done any way your
HTTP server will recognize.
- simple
-
Name of the program to run -- this is MiniVend's
VLINK or
TLINK
- browse
-
Page of the catalog to display
- id=WehUkATn
-
The session
ID
- &
-
Separates session
ID from other other parameters (normal
HTTP)
- mv_arg=99-102
-
An argument which can be used by MiniVend to select page display options.
- &
-
Separates argument from other parameters (normal
HTTP)
- mv_pc=122
-
A unique integer (or source code, if it contains a letter) which prevents caching servers from caching the
URL.