SAS: How to avoid infinite loop in my script and let it run properly?

Question

what my script does is to first scan for xls file in multiple subfolders, then import it and transform it into the target tables according to the source file (1 to 1). It includes transpose and creating new variables(for target table). For now, i havent prepare the script to append all separate tables into 1 big final table.

However, my script been running for 5 hours and is still running. I believe it is in infinite loop. Does anyone notice anything wrong here?

 %macro drive(dir,ext);                                                
 %local filrf rc did memcnt name i;                                                                                                                                                                                
 %let rc=%sysfunc(filename(filrf,&dir));                               
 %let did=%sysfunc(dopen(&filrf));                                     

 %if &did eq 0 %then %do;                                              
   %put Directory &dir cannot be open or does not exist;                 
   %return;                                                              
 %end;                                                                 

 %do i = 1 %to %sysfunc(dnum(&did));                                   
   %let name=%qsysfunc(dread(&did,&i));                                                                                               

   %if %qupcase(%qscan(&name,-1,.)) = %upcase(&ext) %then %do;          
      PROC IMPORT OUT=WORK.out&i  DATAFILE= "&dir/&name"        
        DBMS=csv REPLACE;
        delimiter='09'x;
        getnames=no;        
      RUN;

      proc contents data=out&i noprint out=data_info ;      
      run;

      data _null_;
       set data_info; 
       call symputx(compress("col"||VARNUM),compress(NAME));
       call symputx("cnt",_n_);
      run;

      data _null_;
        set WORK.out&i (obs=2);
        if _n_ = 2 then do;
          tcnt = 0;
            %do i=1 %to &cnt;
                if &&col&i not in ("","Total") then do;
                  trxm = &&col&i;
                  call symputx(compress("trxm"||tcnt),compress(trxm));
                  call symputx("tcnt",tcnt);
                  tcnt+1;
                end;
            %end;
        end;        
      run;

    %put &trxm0;        
    %put &trxm1;
    %put &trxm2;
    %put &tcnt;

data test&i (drop=  %do i=1 %to &cnt; &&col&i.. %end; ); 
        length station $10 voltage $10 year 8 month $20 transformer $10
        Day $20 Date Time MW_Imp MW_Exp MVAR_Imp MVAR_Exp MVA Power_Factor 8;
    format Time hhmm.;      
    set excelout end=last;      
    retain station voltage year month;      
    if _n_ = 1 then do;         
      station = VAR1;       
      voltage = VAR2;       
      year = input(VAR5,4.);        
      month = VAR3;         
    end;        
    if last then do;
      month = strip(put(intnx('month',input(catt(substr(month,1,3),'1960'),monyy.),1),monname10.));
          if month = "January" then year = year+1;      
    end;
        if _n_      4 then do;
        Day = VAR1;
      Date = VAR2;      
      Time = input(VAR3,time.);
      %do j=0 %to &tcnt;        
        transformer = "&&trxm&j..";
            MW_Imp = input(VAR%eval(4+%eval(&j*6)),best32.);
            MW_Exp = input(VAR%eval(5+%eval(&j*6)),best32.);
        MVAR_Imp = input(VAR%eval(6+%eval(&j*6)),best32.);
        MVAR_Exp = input(VAR%eval(7+%eval(&j*6)),best32.);
        MVA = input(VAR%eval(8+%eval(&j*6)),best32.);

        if MVA < 0.001 then Power_Factor = 0;       
        else Power_Factor = max(MW_Imp,MW_Exp)/MVA;
            output;         
      %end;         
    end;        
  run;

  %put &dir/&name;
  %end;                                                                                                                             

       %else %if %qscan(&name,2,.) = %then %do;                                                                                          
         %drive(&dir/%unquote(&name),&ext)                                                                                               
       %end;                                                                                                                             

 %end;                                                                 


 %let rc=%sysfunc(dclose(&did));                                       
%mend drive;                                                          

%let rc=%sysfunc(filename(filrf));                                    
%drive(/data/source/tttt/Files,xls)

This is because the code was prepared in another macro. What i did was to copy the code from another macro into this script. I could be wrong. Please correct me.

I believe my logic may be used incorrectly.

Can anyone spot what was wrong?

Answer 1

You have

%do i = 1 %to %sysfunc(dnum(&did));

And inside that loop you have:

%do i=1 %to &cnt;

That can create an infinite loop because you are resetting the macro variable i. Try changing to:

%do j=1 %to &cnt;

In general, to debug such situations you can add %put statements to see how the value of a macro variable is changing.