Name
Environ Function
Class
Microsoft.VisualBasic.Interaction
Syntax
Environ(expression
)
-
expression
Use: Required
Data Type: String, or a numeric expression
If
expression
is a string, it must be the name of the required environment variable; ifexpression
is numeric, it must be the 1-based ordinal number of the environment variable within the environment table.
Return Value
A String containing the text assigned to
expression
Description
Returns the value assigned to an operating-system environment variable
Rules at a Glance
A zero-length string (“”) is returned if
expression
does not exist in the operating system’s environment-string table or if there is no environment string in the position specified byexpression
.expression
can be either a string or a numeric expression; that is, you can specify one or the other, but not both.
Example
Public Module modMain Public Structure env Dim strVarName As String Dim strValue As String End Structure Public Sub Main( ) Dim intCtr, intPos As Integer Dim strRetVal As String Dim udtEnv As env intCtr = 1 Do strRetVal = Environ(intCtr) If strRetVal <> "" Then intPos = InStr(1, strRetVal, "=") udtEnv.strVarName = Left(strRetVal, intPos - 1) udtEnv.strValue = Mid(strRetVal, intPos + 1) Console.Writeline(udtEnv.strVarName & ": " & udtEnv.strValue) Else Exit Do End If intCtr = intCtr + 1 Loop End Sub End Module
Programming Tips and Gotchas
If
expression
is numeric, both the name and the value of the variable are returned. An equal sign (=) is used to separate ...
Get VB .NET Language in a Nutshell now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.