tarmill

Tarmill Project is a software designed for the compression and encryption of tar files. This program offers the ability to handle each archive member separately, ensuring that any damage that may occur in the middle of the archive does not render the rest of the archive unusable. In such cases, it will be possible to resume at the next readable member header.

Moreover, compressed and encrypted archives created using Tarmill Project remain valid tar files. This means that any well-behaved tar program should be able to list them, but not extract them. Tarmill Project operates as a filter by taking a tar archive on standard input and producing a tar archive on standard output.

One popular way of using Tarmill Project is in backup scripts in collaboration with tar. For instance, in the "tob" package, the following definition can be used:

BACKUPCMD='tar -c -S -T $FILELIST -f - | tarmill -F1500 -m8M -C6M zip 3 list encrypt /etc/tob/key >$BACKUPDEV'

This command helps in creating backups by allowing users to set specific parameters such as file size and compression levels. Additionally, Tarmill Project has encryption capabilities that make it possible to protect data using user-defined keys.

Finally, for restoring archives created using Tarmill Project, the following command can be used:

RESTORECMD='tarmill decrypt /etc/tob/key unzip list.'

Overall, Tarmill Project is an excellent software that offers reliable compression and encryption features for tar files. It is valuable for backup purposes and provides flexibility in terms of customization.