/* listovars Daniel Brockman 20120119 Put list of ds vars in Macro var. */

/* options ls=80 mprint symbolgen mlogic ;  /* test */

%macro listovars(dsn) ;  
   /* listovars uses proc contents to read the names of vars from a dataset.
   /* listovars puts the list of names in global macro variable glist.
   /*
   /* dsn = dataset from which to read variable names.
   /*
   /* Example:
   /*   %global glist ;
   /*   %listovars(mylib.mydataset) ;
   /*   %let mylist = &glist ;
   /* */

      %global glist ;

      proc contents data=&dsn out=listovars_a noprint ;
      run;

      data _NULL_ ;
         length nc $8. ;               /* character rep of number */
         set listovars_a ;
         nc=left(put(_N_,8.)) ;
         call symput('L'||nc,NAME) ;   /* create &L1 &L2 &L3, etc. */
         call symput('NNN',nc) ;      /* number of items */
      run;

      %let glist= ;       /* init */
      %let ii=1 ;
      %do %while ( &ii le &NNN ) ;
        %let glist=&glist &&L&ii ;        /* compose list */
        %let ii=%eval(&ii+1) ; 
      %end ;
      
%mend listovars ;

/* ------------------------------------------------------------------- */

/* Test 
data bozo ; 
format bravo $18. ;
input alpha  bravo $ charlie ;
cards;
1 walter 5
2 yves   8
3 zelda  9
;
proc print data=bozo; run;

%listovars(bozo) ;
%let YAMHEAD=&glist ;
%put YAMHEAD: &YAMHEAD ;

/* End Test */
/* ------------------------------------------------------------------- */