/*

/ Program   : dropvars.sas
/ Version   : 1.0
/ Author    : Roland Rashleigh-Berry
/ Date      : 04-May-2011
/ Purpose   : To drop a list of unwanted variables in a list of datasets.
/ SubMacros : %dsall %words %varlist %quotelst
/ Notes     : You can use the _all_ notation to refer to all the datasets in a
/             library.
/ Usage     : %dropvars(work._all,x1 x2)
/ 
/===============================================================================
/ PARAMETERS:
/-------name------- -------------------------description------------------------
/ list              (pos) List of datasets. The _all_ notation can be used.
/ drop              (pos) List of variables to drop.
/===============================================================================
/ AMENDMENT HISTORY:
/ init --date-- mod-id ----------------------description------------------------
/ rrb  29Mar07         Put out "macro called" message plus header tidy
/ rrb  04May11         Code tidy
/===============================================================================
/ This is public domain software. No guarantee as to suitability or accuracy is
/ given or implied. User uses this code entirely at their own risk.
/=============================================================================*/

%put MACRO CALLED: dropvars v1.0;

%macro dropvars(list,drop);

  %local dropvars varlist i j;
  %dsall(&list)
  %let drop=%quotelst(%upcase(&drop));

  %do i=1 %to %words(&_dsall_);
    %let dropvars=;
    %let varlist=%varlist(%scan(&_dsall_,&i,%str( )));
    %do j=1 %to %words(&varlist);
      %if %index(&drop,"%upcase(%scan(&varlist,&j,%str( )))") 
        %then %let dropvars=&dropvars %scan(&varlist,&j,%str( ));
    %end;
    %if %length(&dropvars) %then %do;
      data %scan(&_dsall_,&i,%str( ));
        set %scan(&_dsall_,&i,%str( ));
        drop &dropvars;
      run;
    %end;
  %end;

%mend dropvars;