How do I write a macro to…split my data set into multiple files?

A very common question on forums and help boards appears to be “How do I write a macro to do XYX?”. Often times a macro isn’t required.┬áThis is part one of an ongoing series into how to accomplish a task WITHOUT using a macro.

The first example answers the question of how to Split a data set into multiple files. Any file generated using a file statement can be generated using this method. I will be using the FILEVAR option of a file statement to split the SASHELP.CARS data set into multiple text files, one for each Make. The process and code is below, hope you find it helpful!

This is a two step process:

  1. Sort the file
  2. Generate the output using a Data Step

BY make;


SET cars; *Dataset to be exported;
BY make; *Variable that file is to be split on;

*Create path to file that is to be exported;
if first.make then out_file=cats(‘/folders/myfolders/’, trim(make));

file temp filevar=out_file dlm=’,’ dsd;

*If first value of make then output column names;
if first.make then
put ‘Make, Model, MPG_HIGHWAY, MPG_CITY’;

*Output variables;
put make model mpg_highway mpg_city;