docs/111265: Clarify how to set common shell variables

[Victor Engmark]

>Number:         111265
>Category:       docs
>Synopsis:       Clarify how to set common shell variables
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-doc
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          change-request
>Submitter-Id:   current-users
>Arrival-Date:   Thu Apr 05 10:20:03 GMT 2007
>Closed-Date:
>Last-Modified:
>Originator:     Victor Engmark
>Release:        
>Organization:
>Environment:
>Description:
Until reading section 3.9.1, it looks like section 3.9 advocates setting all shell variables using setenv / export. Since this is not the case for at least $SHELL and $TERM (and, I presume, $OSTYPE and $MACHTYPE), new users might get unexpected results when trying to change variables.

Assuming that the handbook is used as a reference, maybe the information should be re-organized to avoid misunderstandings.
>How-To-Repeat:

>Fix:
The explanations of the individual shell variables in section 3.9 could be moved into the sections discussing their use (such as 3.10, "Editors", for $EDITOR and 3.9.1, "Changing Your Shell", for $SHELL).

Another option would be to add a warning that some variables should not be set using setenv / export, or explicitly point out which commands should be used / link to the relevant documentation.
>Release-Note:
>Audit-Trail:
>Unformatted: