SAS: Set current folder to the folder containing the running program

Question

I've just started learning SAS because I'm required to use it for a statistics course. For this course, the university provides SAS 9.2 through their virtual-machine setup: I make a reservation in their system, they generate a VM on one of their servers, and I connect to the VM using Microsoft's Remote Desktop client. The virtual machines are generated and erased per session; settings are reset every time, and files must be stored on my client computer (which is accessible in the VM by a UNC path).

Within this setup, when I open a program file stored on my laptop, I've only been able to access the accompanying data files (each stored in the same folder as the program) either by hardcoding the full path or by updating the "current folder" setting at the beginning of each session. The first is problematic because it means the program won't run anywhere else - in particular, when I email it to the professor. The second is inconvenient, because browsing to this particular UNC path is time consuming, and I already have to browse to the same path to open the program file.

I want to make this easier by programmatically setting the current folder to the folder containing the program. Then I could just open the file and get to work. I've found some examples of getting the filename of the program file, of getting the path to a fileref, and of (link limit exceeded) setting the current folder, but I haven't been able to combine them in the right way. Please connect the dots for me.

Answer 1

To programmatically change the Windows current directory from SAS, you can use the X command, which is what really happens when you use the "Change current folder" dialog box:

x 'cd "\\computername\share name\folder"';

You can also do this using the SYSTEM data step function, a method I prefer because you get a return code (but more typing of course):

data _null_;
   rc = system( 'cd "\\computername\share name\folder"' );
   if rc = 0 
      then putlog 'Command successful';
      else putlog 'Command failed';
run;

Note the UNC path is surrounded with double-quotes, which is necessary if the path contains blanks.

Of course, this still requires you to manually type in the command, but it might be something you could add to the program source code. If your VM environment allowed you to maintain some permanent presence on the server, you could save this command into a start-up file.

I would ask your professor for advice; if you are working with data given to you as part of your class, you may only need to send just the source code. On the other hand, if you are creating output data as part of your assignment, your professor might want your to deliver source code and SAS data sets. Surely he or she will have some procedure.