[rdiff-backup-users] Instrumenting rdiff-backup to report progress during run?

[Josh Lehan]

Hello.  I am wondering if there is currently any way to get rdiff-backup 
to display its progress during a backup run.

Ideally, something like "rsync --progress" would be desirable.  This 
would have all the information necessary for seeing what is going on at 
any given moment.

I looked through the current list of features and options, and found no 
way to enable a progress report.  I can increase verbosity and get a lot 
of debugging information, but that's about it.

What I'm looking for is a way to see the following, during a backup run:

* Name of current file being examined

* Decision made regarding that file (skip it as unchanged, increment 
from it, copy it completely, create new file, delete old file, and so on)

* Total count of files examined so far

* Total size, in bytes, of files examined so far

* For files that are not being skipped, intra-file progress information, 
such as number of bytes compared or copied so far, and number of bytes 
remaining

* Total number of files on the source (because rdiff-backup walks all 
directories in a single pass, unlike rsync, this information would be 
very difficult for rdiff-backup to know in advance without adding 
another pass)

* Total number of bytes on the source

The method of communicating this information should be separate from the 
usual backup logs, because the backup logs are buffered.  This progress 
information should be visible in realtime, however, or it isn't very useful.

Perhaps a named pipe, or an additional file descriptor, would be a good 
way of communicating this status information.  Suggestions are welcome.

Josh Lehan