dlon - turn on transaction logging
Dlon turns on transaction logging and records the name of the
program doing the RMSfile changes.
Program is a null terminated string to be used as the program
name when writing entries to the log file. The maximum length of
this string is defined in the include file
If program is an empty string or a NULL pointer, the current
program name is cleared.
Transaction logging is normally on when a program begins. Calling
dlon when transaction logging is already on does nothing more
than change the program name.