F - stands for File Management. This is bread and butter work for SAS, with standard file handling features such as:

• procs for quick import export
• put / input for variable level control
• byte streaming for character level control
• functions for file movement (eg fcopy)
• ability to load an entire file into one variable (proc lua)

The upgrade of LUA in 9.4M6 opens up more possibilities for file management with access to the IO library (https://www.lua.org/manual/5.1/manual.html#5.7).

Files received from the frontend are easily captured by SAS 4GL via the automatic "_WEBIN_nameXX" and "_WEBIN_FILEREFXX" macro variable arrays (which point to copies of the received files).

Sending files back to the frontend simply involves setting the http headers ("stpsrv_header" function) and writing content directly to the "_webout" fileref.

These are the mechanisms in use in this 30 second demo video. A CSV file is uploaded to Data Controller, the data is reviewed and approved, and the table is finally downloaded as a .SAS program file.