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Q139625: HOWTO: Use and Call the GetUserName API

Article: Q139625
Product(s): Microsoft FoxPro
Version(s): 
Operating System(s): 
Keyword(s): kbvfp300 kbvfp500 kbvfp600
Last Modified: 28-JUL-1999

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, versions 3.0, 5.0, 6.0 
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SUMMARY
=======

Windows NT and Windows 95 may require that users log on to a computer or
network. On occasion, you may want to use the login user id for your
application. By using the GetUserName API call, you can discover the name of the
user who is currently logged on to the system. This article shows by example how
to use and call the Win32 GetUserName API.

MORE INFORMATION
================

Having the user id of the currently logged in user can be helpful in multiuser
programming for situations such as updating a table field with the user id of a
user who has a record locked.

The GetUserName API call is specific to Windows 95 and Windows NT and cannot be
used in Windows or Windows for WorkGroups.

The return value held in the variable lpUserIDBuffer is null terminated, so to
get just the user ID, the following sample code trims the actual return value by
using the LEFT, LEN, and ALLTRIM functions.

Sample Code
-----------

     **--------------------------------------------------------**
     ** Program: Getuser.prg                                   **
     ** Purpose: Demonstrates how to use and call the Win32    **
     ** GetUserName API.                                       **
     **--------------------------------------------------------**
     PUBLIC  lpUserIDBuffer, ;
             nBufferSize, ;
             RetVal

     RetVal         = 0
     lpUserIDBuffer = SPACE(25) && Return buffer for user ID string
     nBufferSize    = 25        && Size of user ID return buffer

     DECLARE INTEGER GetUserName IN Win32API AS GetName ;
             STRING  @lpUserIDBuffer, ;
             INTEGER @nBufferSize

     RetVal=GetName(@lpUserIDBuffer, @nBufferSize)

     DEFINE WINDOW ShowInfo FROM 0,0 TO 5,70 ;
             FLOAT CLOSE ;
             TITLES "User ID Information" ;
             FONT "Courier",10

     ACTIVATE WINDOW ShowInfo
     MOVE WINDOW ShowInfo CENTER

     @ 0,1 SAY "User ID  : " + ;
       LEFT(lpUserIDBuffer,nbuffersize-1)

General Information
-------------------

For an alternative to this method that will work on any of the platforms,
including Windows 3.1 and Windows for Workgroups, please see the following
article in the Microsoft Knowledge Base:

  Q99921 HOWTO: Obtain Network User IDs from Within FoxPro

REFERENCES
==========

For additional information on this API function, please refer to the online
Win32API help file under the "GetUserName" topic. Note that this help file is
available only on the compact disc version of Visual FoxPro. It is not shipped
with the floppy disk version.

For more information about the DECLARE DLL command, please refer to the Visual
FoxPro online Help file.

Additional query words:

======================================================================
Keywords          : kbvfp300 kbvfp500 kbvfp600 
Technology        : kbVFPsearch kbAudDeveloper kbVFP300 kbVFP500 kbVFP600
Issue type        : kbhowto

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