/*<pre><b>
/ Program   : alluniq.sas
/ Version   : 1.0
/ Author    : Roland Rashleigh-Berry
/ Date      : 31-Jul-2007
/ Purpose   : To create a dataset with all unique occurences of a variable
/             throughout a library.
/ SubMacros : %hasvars
/ Notes     : The output dataset will be in sorted order if valid
/ Usage     : %alluniq(in,subject,allsubj)
/ 
/===============================================================================
/ PARAMETERS:
/-------name------- -------------------------description------------------------
/ libref            (pos) Libref
/ variable          (pos) Variable name
/ dsout             (pos) Output dataset name (defaults to "alluniq")
/===============================================================================
/ AMENDMENT HISTORY:
/ init --date-- mod-id ----------------------description------------------------
/ rrb  16Jun03         Create null output dataset and use %hasvars
/ rrb  29Mar07         Put out "macro called" message plus header tidy
/ rrb  31Jul07         Header 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: alluniq v1.0;

%macro alluniq(libref,variable,dsout);

%if not %length(&libref) %then %let libref=%sysfunc(getoption(user));
%if not %length(&libref) %then %let libref=work;

%if not %length(&variable) %then %do;
  %put ERROR: (alluniq) No variable name specified;
  %goto skip;
%end;

%if not %length(&dsout) %then %let dsout=alluniq;


*- create null output dataset -;
data &dsout;
_u_m_b_j=.;
run;


data _null_;
  set sashelp.vcolumn(where=(libname="%upcase(&libref)" 
                             and upcase(name)="%upcase(&variable)"));
  if _n_=1 then do;
    call execute('proc sort nodupkey data='||trim(libname)||'.'||trim(memname)||
    "(keep=&variable) out=&dsout;by &variable;run;");
  end;
  else do;
    call execute('proc sort nodupkey data='||trim(libname)||'.'||trim(memname)||
    "(keep=&variable) out=_alluniq;by &variable;");
    call execute('proc append base=&dsout data=_alluniq;run;');
  end;
run;


%if %hasvars(&dsout,&variable) %then %do;
  proc sort nodupkey data=&dsout;
    by &variable;
  run;
%end;
%else %put ERROR: (alluniq) Library &libref has no instances of variable &variable;


proc datasets nolist;
  delete _alluniq;
run;
quit;


%skip:
%mend;