Subroutines and external files

• Overview
  • Subroutines and diversions
  • Handling errors that arise during processing of a subroutine
• Linking external files to [B/D]
• Removing links to external files
• Re-initialising macro handling
• Defining export channels
• Unconditionally switching program flow
• Temporarily diverting program flow to subroutines
• Redirecting output
• User-defined error handling
• Defining additional search paths
• Updating shared external files
• Returning from subroutines