All DD routines (except the monitor programs) do not print
any status or information to stdout or stderr. They
instead write the information into a string and call
a routine dd_log.
The syntax is dd_log(int info_id, char *msg), where
info_id is an identifier for the string message.
The currently supported info_id' s are DD_INFO and
DD_ERROR.
dd_log currently simply prints the string to stdout
or stderr (depending whether info_id is DD_INFO or
DD_ERROR.
This behaviour can of course be changed by simply changing
dd_log, e.g. popping up a window displaying the
information, a feature that might be desirable in a distributed system.