/*<pre><b>
/ Program   : numchars.sas
/ Version   : 1.0
/ Author    : Roland Rashleigh-Berry
/ Date      : 04-May-2011
/ Purpose   : To create a list of character variables that contain numeric-like
/             text.
/ SubMacros : %nvarsc
/ Notes     : It is not possible to implement this as a function-style macro due
/             to the data step boundary so the results will be written out to a
/             global macro variable. You can use this list in the char2num macro
/             that converts character fields to numeric fields. This macro uses
/             the verify function with the test string '0123456789., ' to test
/             for numeric-like entries which is not a perfect test. Using this
/             test then if a field is character and all-missing then it will be
/             assumed to be a possible numeric field.
/ Usage     : %numchars(dsname,globvar=_numchars_);
/             %put ######## &_numchars_;
/===============================================================================
/ PARAMETERS:
/-------name------- -------------------------description------------------------
/ ds                Dataset (pos) (must be pure dataset name and have no keep,
/                   drop, where or rename associated with it).
/ globvar=_numchars_    Name of the global macro variable to set up to contain
/                   the list of all-missing variables.
/===============================================================================
/ 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: numchars v1.0;

%macro numchars(ds,globvar=_numchars_);

  %local err;
  %let err=ERR%str(OR);

  %global &globvar;
  %let &globvar=;

  %let nvarsc=%nvarsc(&ds);

  %if &nvarsc EQ 0 %then %do;
    %put &err: (numchars) Data set &ds does not contain any character variables;
    %goto exit;
  %end;


  data _null_;
    array _num {&nvarsc} $ 1 _temporary_ (&nvarsc*'1');
    set &ds end=last;
    array _char (*) _character_;
    do i=1 to &nvarsc;
      if verify(_char(i),'0123456789., ') then _num(i)='0';
    end;
    if last then do;
      do i=1 to &nvarsc;
        if _num(i) EQ '1' then call execute('%let &globvar=&&&globvar '||
          trim(vname(_char(i)))||';');
      end;
    end;
  run;

  %goto skip;
  %exit: %put &err: (numchars) Leaving macro due to problem(s) listed;
  %skip:

%mend numchars;