Steps:

1. Store the number of observations in a data set to a macro variable (RECCOUNT)
2. Increment a variable (I) fromone to RECOUNT using a %DO loop

3. Use the FIRSTOBS option in a DATA step to advance to the record I
4. Store record values to macro variables using CALL SYMPUT
5. Perform any desired PROC and DATA steps

EXAMPLE:

In the following example, a log file (DATALOG) has been created of all the data sets in a library named TEST. Periodically, it is necessary to print the contents of these data sets into a series of quick reports. DATALOG consists of two columns, FILENM (the file name) and DESC (a short description). The reports should be formatted with a standard PROC PRINT and have a title consisting of the table description. The following piece of code accomplishes that task.

/* Macro to SCAN through DATALOG */
%macro scanloop(scanfile,field1,field2);
   /* First obtain the number of */
   /* records in DATALOG */
   data _null_;
      if 0 then set &scanfile nobs=x;
	  call symput("reccount",x);
	  stop;
   run;
   /* loop from one to number of records */
   %do i=1 %to &reccount;
   /* Advance to the Ith record */
   data _null_;
      set &scanfile(firstobs=&i);
      /* store the variables of interest in macro variables */
      call symput('var1',&field1);
	  call symput('var2',&field2);
	  stop;
   run;
   /* now perform the tasks that wish repeated for each observation */
   proc print data=&var1;
      title "&var2";
   %end;
%mend scanloop;
/* Call SCANLOOP */
%SCANLOOP(DATALOG,FILENM,DESC);
RUN;