DEFIANT-FG (FG) is a light-weight, command-line utility written to check file (object) integrity within a directory structure. The hash of the object is stored within a database located within the root of the given directory. You can easily move this file with the directory between computers. Additional objects are added to the database at the next run.
Run periodically to check the integrity of your static archive or backup. New and unknown objects are added to the database at next run, so you can easily grow the directory. FG will, however, log failed hashes (such as bit rot or corrupted objects) and missing objects.
Each object is checked against a known hash. If the object has not been seen by FG yet, a hash will be generated and stored in the database. Further running of the script will result in the object being checked against the hash. Some objects change, you know which are corrupted and need restoring for backup. Many integrity fails informs you that your media is damaged, such as faulted hard drive.
The object (such as picture, video or document) is put through a mathematical formula to return a unique code for each object. It's unlikely two different objects will contain the same code. This is why it's a great method to check objects have not been changed. For example, if bit rot occurs, a single bit may change from a 1 to a 0 or vice versa which may not make much difference to a text file, but completely change a picture or damage a video.
FG uses the SHA-256 algorithm to generate hashes. For example the word "DEFIANT-FG" run through SHA-256 will become: 2948a9654f6276d7de69e60c9304ece662f9ba17c667e6dfcd4dacf38661192b. If I change the last character from "G" to "g" and run again, the hash will completely change: 121089879462d657a7938d8e44b909d6cabfde31f525a13c04be0a534ee61f5e
On Debian based operating systems (such as Ubuntu, Linux Mint), download the deb package. On desktop versions, open package and click install package.
Or, via command line:
Download
wget https://github.com/karlh001/defiant-fg/raw/main/dist/dfg_amd64.deb
Install (as root)
dpkg --install dfg_amd64.deb
Done.
Alternatively, download the release, extract and follow Install.
| Architecture | Linux | Windows | .deb | FreeBSD | OpenBSD | NetBSD | darwin |
|---|---|---|---|---|---|---|---|
| amd64 | Download | Download | Download | Download | Download | Download | Download |
| i386 (32-bit) | Download | Download | |||||
| Arm64 | Download | Download | Download | Download | Download | ||
| Arm6 | Download | Download |
Click here for releases.
On a Debian-based operating system, such as Ubuntu or Linux Mint, download the deb installer located in the dist directory.
The binaries are available in the dist directory. Copy this to your bin directory to run. Alternatively, in the terminal run ./defiant-fg to execute the program.
If you need to run another platform, please read the build guide.
Run the command-line tool:
dfg -d /path/dir/
Let's say you have a pictures folder on an external hard drive located /mnt/hdd/Pictures/. To scan this directory use:
dfg -d /mnt/hdd/Pictures/
If you have scanned this directory before, there will be a database file with the file hashes stored within. If not present, FG will ask you to confirm; type y to confirm.
FG will look through the directory structure at every file. If the file is known to FG, the previous hash will be checked against the current hash - if it changes you will be notified to restore from backup. If the file is not known, a new hash will be generated and stored into the database.
Finally, the database file is used to check for missing files
To save a log file within the scanned directory, add the -l flag. The log file will be named dfg.log.
To run the application to on a schedule or through a script, add the -l and -s flags to skip user inputs on the terminal. Read about flags here.
dfg -l -s -d /path/to/files/
This file is portable and should move with the directory, such as back up to remote storage or migration to new drive. It contains the path to file, hash of file, and basic meta data. Database file is named dfg.db; to change the location of the database file use -db /path/to/file.sql.
This read me is designed to be brief to allow you to start enjoying FG as soon as possible. For more detail, please read the manual.
If you would like to contribute, please commit changes and I will be happy for the help. Also if you find this tool useful please buy me a coffee or PayPal donation.