HOW CAN I CHECK IF A DIRECTORY ALREADY EXISTS AND IF NOT, CREATE IT?

The macro works by using the %SYSFUNC macro function to check to see if a filename assigns correctly and if so puts out a message to the SAS log to say the directory exists. If the fileref does not assign correctly, due to the directory not existing, then the following code uses the %SYSEXEC macro function to create a new directory using the (dir =) parameter passed to the macro.

To demonstrate this, in this example we check for a directory that we know exists, c:\temp and then a directory that may not exist, c:\temp\sascode.

%macro chk_dir(dir=) ;
   options noxwait;
   %local rc fileref ;
   %let rc = %sysfunc(filename(fileref,&dir)) ;
   %if %sysfunc(fexist(&fileref))  %then
      %put NOTE: The directory "&dir" exists ;
   %else
     %do ;
         %sysexec md   &dir ;
         %put %sysfunc(sysmsg()) The directory has been created. ;
   %end ;
   %let rc=%sysfunc(filename(fileref)) ;
%mend chk_dir ;

%chk_dir(dir=c:\temp) ;    %*   <==  your directory specification goes here ;
%chk_dir(dir=c:\temp\sascode)  

Note: The above code has been tested using SAS 8.2 on the Windows operating system.