-= bit_rot_detector =-
==========================

bit_rot_detector, or brd, is a tool to scan a directory tree and check each file
for corruption caused by damage to the physical storage medium or by damage from
malicious programs. Files are fingerprinted using the SHA-1 algorithm. File
fingerprints, sizes, and modification times are stored in a SQLite database.

Multiple unrelated directory trees can be stored in the same database. All
trees are identified by the base directory, or root, as specified on the 
command-line. Note that the following are considered different trees:
    some_dir/
    ./some_dir/

Subtrees can be specified anywhere roots can as long as the full root to subtree
path is specified. However, the subtree must already exist in the database. If
the subtree is not currently in the database, it will be considered to be a
new root. For example, the following will scan some_dir as a new root and add 
all of its children to the database, then scan the subtree some_subtree for
problems and/or changes:
    # Add new root
    brd scan some_dir
    # Scan only part of a root for problems and changes.
    brd scan some_dir/some_subtree

Note: the default behavior for scan is to update the database for any files
that are newer than the database record. Files that have been tampered with will
likely be flagged as updated and not as damaged. To properly check for files
that have been tampered with, run scan with the --dry-run option.

Since scanning large trees or trees with large files can take quite a while,
it is possible to exclude files in directories that have recently been checked
via the -s option. How recent is "recent" is controlled by the --expr option and
defaults to 30 days.

The integrity of the database can be checked via the checkdb subcommand.

In addition to checking files for corruption, brd provides the ability to search
the database for duplicate files and subtrees, as well as diff subtrees.
See the dupe_files, dupe_trees, and diff subcommands for details.

General and subcommand help can be viewed via the -h option:
    brd -h
    brd scan -h

-= Requirements =-
==========================
* python3 - tested with Python 3.3.0

-= Homepage =-
==========================
http://github.com/jsbackus/brd

-= Copyright =-
==========================
(c) 2013 Jeff Backus
See LICENSE for information regarding use and distribution.