Date:         Mon, 28 Sep 2009 13:40:29 -0700
Reply-To:     Anaconda <rune@FASTLANE.NO>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Anaconda <rune@FASTLANE.NO>
Organization: http://groups.google.com
Subject:      Macrotrouble - ERROR: Required operator not found in expression
Comments: To: sas-l@uga.edu
Content-Type: text/plain; charset=ISO-8859-1

The macro below is supposed to check if a dataset exists or not. And
if it exists, then count the number of observations in it. What does
the error message in the SAS log mean?

- Anaconda

%macro nobs(dsn);
   %if exist("&dsn") %then %do;
      dsid = open("&dsn", "i");
      nobs = attrn(dsid, "nlobs");
   %end;
   %else nobs = . ;
   rc = close(dsid);
%mend;
%nobs(Sashelp.Class) ;


/*
14353  %macro nobs(dsn);
14354     %if exist("&dsn") %then %do;
14355        dsid = open("&dsn", "i");
14356        nobs = attrn(dsid, "nlobs");
14357     %end;
14358     %else nobs = . ;
14359     rc = close(dsid);
14360  %mend;
14361  %nobs(Sashelp.Class) ;
ERROR: Required operator not found in expression: exist("&dsn")
ERROR: The macro NOBS will stop executing.


*/