variables that may be sent through the
.Dv TELNET ENVIRON
option.
-The initial set of variables is taken from the users
-environment, with only the
-.Ev DISPLAY
-and
-.Ev PRINTER
-variables being exported by default.
-The
-.Ev USER
-variable is also exported if the
-.Fl a
-or
-.Fl l
-options are used.
+The initial set of variables is populated with the
+contents of the following environment variables, if
+present:
+.Ev USER , PRINTER , DISPLAY , TERM , COLUMNS , LINES.
+
+Only the first three are exported, by default.
.Pp
Valid arguments for the
.Ic environ
command are:
.Bl -tag -width Fl
-.It Ic define Ar variable value
+.It Ic define Ar variable [value]
Define the variable
.Ar variable
to have a value of
.Ar value .
+If value is empty, the value is taken from the environment variable.
Any variables defined by this command are automatically exported.
The
.Ar value