The following program can be used to extract files from a tar tape which
contains read errors. It is used as a filter whose output should be piped
into tar thus:

	badtar -f /dev/rmt16 -l log_file | tar xf -

This program is not perfect. It cannot read what cannot be read, but it
will continue over read errors, pad files to suitable lengths when blocks
are missing, ignore files whose header tar blocks are mangled etc...

The log file (-l flag) gives a list of all files found, indicates which of 
them were padded, shows where blocks were deleted (ie files were lost)
and where bad blocks occured on the tape. You can get a good idea from this
list where files will have been mangled or lost. All error messages begin with
*** which makes life easier to find errors in a long list.

Badtar was written by Mike Williams and appeared in net.sources in 1986.
I have worked on the code one day I could not read my backup tape... The
ownership overwriting has been written specially for kit. Badtar may be
used apart from kit, of course, as a standalone tool.

If you have suggestions on how to improve badtar, I would be pleased to
hear about it. However, I'd like to keep it small, being part of kit
delivery.

	Raphael Manfredi <ram@eiffel.com>
