AT&T 6300 Programmer's Manual page 244

ENVIRON
Statement
Allows modification of parameters in
GWBASIC's Environment String Table.
Syntax
parm-id
Remarks
7-88
ENVIRON parm-id
=
[text[;]]
is a valid string expression containing the new Environ-
ment String parameter
The ENVIRON statement may be used, for
example, to change the "PATH" parameter for
a child process. Parameters may also be
passed to a child process by inventing a new
environment parameter.
Rules
• "parm-id" is the name of the parameter such
as "PATH."
• "parm-id" must be separated from 'text' by '='
or ' , (blank) such as "PATH='. ENVIRON
takes everything to the left of the first blank or
"=" as the "parm-id," and everything to the
right as 'text.'
• "text" is the new parameter text. If "text" is a
null string, or consists only of ";" (a single
semicolon, such as "PATH=;") then the
parameter (including "parm-id=") is removed
from the Environment String Table and the
Table is compressed.