Web Authoring Seminar: File Systems

File Systems

The diagram below shows a sample directory tree. The boxes outline the Network Server and AFS filespaces. What is visible to you, and how you refer to it, depends upon where you are. The lighter portion of both trees, from "userid" on down, is visible to a person who is logged in to that particular userid. The portion in green, the AFS "public" directory and below, is visible to anyone who is logged in to any Lehigh account. The bright green portion of this, the "www-data" directory and below, is visible to anyone on the Web. The two dashed-line arrows, from "ahome" and "~userid" respectively, indicate that these are aliases; in other words, they are equivalent to the items they point to, rather than containing them.

The files in the "www-data" directory can be edited from either a workstation or from the Network Server. It is important to note, however, that the way you refer to a particular location differs depending on where you are. For example, to refer to "subdir1":

The absolute path:
/afs/cc.lehigh.edu/home/userid/public/www-data/subdir1/
From an AFS workstation:
/home/userid/public/www-data/subdir1/
From the Network Server: (note the change of "home" to "ahome")
/ahome/userid/public/www-data/subdir1/
In a URL:
/~userid/subdir1/

This means that the way you refer to a file in order to edit it, for example, is not exactly the same as the way you would refer to it in a hyperlink. Notice in particular how "~userid" serves as a shorthand for "home/userid/public/www-data."

SDR, 11 Jun 1995.