Date:         Fri, 9 Feb 2001 01:31:19 -0500
Reply-To:     "David L. Ward" <dward@INTERNEXT-INC.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         "David L. Ward" <dward@INTERNEXT-INC.COM>
Subject:      Re: Determining the existence of a macro variable
Comments: cc: jack@WATARTS.UWATERLOO.CA
Content-Type: text/plain; charset="iso-8859-1"

You can check if a macro variable has been defined by checking the
dictionary.macro or sashelp.vmacro view.  Here's a macro to do it in pure
macro code:
%macro mvscope (_var);
  /** OPEN THE VMACRO VIEW WHICH CONTAINS INFO ABOUT MACOR VARS **/
  %let dsid=%sysfunc(open(sashelp.vmacro (where=(name="%upcase(&_var)"))));
  /** FETCH A RECORD INTO THE PDV IF IT EXISTS **/
  %let rc=%sysfunc(fetch(&dsid));
  /** RETURN VARNUM 1, THE SCOPE **/
  %sysfunc(getvarc(&dsid,1))
  /** CLOSE THE VIEW **/
  %let rc=%sysfunc(close(&dsid));
%mend;

Example:

%if %mvscope(var1)=GLOBAL %then %do;
%end;

HTH
David Ward

---------------------
I want to conditionally perform some action in a macro
based on the existence of a macro variable being passed
through the Application Dispatcher.  Is there some
straight-forward way of determining the existence of
a macro variable?  Any assistance would be appreciated.

        Cheers,

                Jack Cooper



------------------------------------
President
InterNext, Inc.
Software for the Internet Generation
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