Par2cmdline uses Reed-Solomon error-correcting codes to generate and verify PAR2 recovery files. These files can be distributed alongside the source files or stored together with back-ups to protect against transmission errors or bit rot, the degradation of storage media over time. Unlike a simple checksum, PAR2 doesn't merely detect errors: as long as the damage isn't too extensive (and smaller than the size of the recovery file), it can even repair them.

Rdup is a utility inspired by rsync and the plan9 way of doing backups. Rdup itself does not backup anything, it only print a list of absolute file names to standard output. Auxiliary scripts are needed that act on this list and implement the backup strategy.

wimlib is a C library and set of command-line utilities for creating, modifying, extracting, and mounting archives in the Windows Imaging Format (WIM files). It can capture and apply WIMs directly from and to NTFS volumes using ntfs-3g, preserving NTFS-specific attributes.

borgmatic is simple, configuration-driven backup software for servers and workstations. Protect your files with client-side encryption. Backup your databases too. Monitor it all with integrated third-party services. borgmatic is powered by borg.

Grsync is a simple graphical interface using GTK for the rsync command line program. It currently supports only a limited set of the most important rsync features, but can be used effectively for local directory synchronization.

rsnapshot is a file system snapshot utility based on rsync. rsnapshot makes it easy to make periodic snapshots of local machines, and remote machines over SSH. To reduce the disk space required for each backup, rsnapshot uses hard links to deduplicate identical files.

Hdup2 is a backup utility, its aim is to make backup really simple. The backup scheduling is done by means of a cron job. It supports an include/exclude mechanism, remote backups, encrypted backups and split backups (called chunks) to allow easy burning to CD/DVD.

Libarchive provides a flexible interface for reading and writing archives in various formats such as tar and cpio. Libarchive also supports reading and writing archives compressed using various compression filters such as gzip and bzip2. The library is inherently stream-oriented; readers serially iterate through the archive, writers serially add things to the archive. In particular, note that there is currently no built-in support for random access nor for in-place modification. This package provides the bsdcat, bsdcpio and bsdtar commands.

Borg is a deduplicating backup program. Optionally, it supports compression and authenticated encryption. The main goal of Borg is to provide an efficient and secure way to backup data. The data deduplication technique used makes Borg suitable for daily backups since only changes are stored. The authenticated encryption technique makes it suitable for storing backups on untrusted computers.

Rdiff-backup backs up one directory to another, possibly over a network. The target directory ends up a copy of the source directory, but extra reverse diffs are stored in a special subdirectory of that target directory, so you can still recover files lost some time ago. The idea is to combine the best features of a mirror and an incremental backup. Rdiff-backup also preserves subdirectories, hard links, dev files, permissions, uid/gid ownership, modification times, extended attributes, acls, and resource forks. Also, rdiff-backup can operate in a bandwidth efficient manner over a pipe, like rsync. Thus you can use rdiff-backup and ssh to securely back a hard drive up to a remote location, and only the differences will be transmitted. Finally, rdiff-backup is easy to use and settings have sensible defaults.

With dirvish you can maintain a set of complete images of your file systems with unattended creation and expiration. A dirvish backup vault is like a time machine for your data.

Btrbk is a backup tool for Btrfs subvolumes, taking advantage of Btrfs specific capabilities to create atomic snapshots and transfer them incrementally to your backup locations. The source and target locations are specified in a config file, which allows easily configuring simple scenarios like e.g. a laptop with locally attached backup disks, as well as more complex ones, e.g. a server receiving backups from several hosts via SSH, with different retention policy. It has features such as:

• atomic snapshots

• incremental backups

• flexible retention policy

• backups to multiple destinations

• transfer via SSH

• resume backups (for removable and mobile devices)

• archive to offline storage

• encrypted backups to non-btrfs storage

• wildcard subvolumes (useful for Docker and LXC containers)

• transaction log

• comprehensive list and statistics output

• resolve and trace Btrfs parent-child and received-from relationships

• list file changes between backups

• calculate accurate disk space usage based on block regions.

Btrbk is designed to run as a cron job for triggering periodic snapshots and backups, as well as from the command line (e.g. for instantly creating additional snapshots).

Disarchive can disassemble software archives into data and metadata. The goal is to create a small amount of metadata that can be used to recreate a software archive bit-for-bit from the original files. For example, a software archive made using tar and Gzip will need to describe the order of files in the tarball and the compression parameters used by Gzip.

Dump examines files in a file system, determines which ones need to be backed up, and copies those files to a specified disk, tape or other storage medium. Subsequent incremental backups can then be layered on top of the full backup. The restore command performs the inverse function of dump; it can restore a full backup of a file system. Single files and directory subtrees may also be restored from full or partial backups in interactive mode.

ZBackup is a globally-deduplicating backup tool, based on the ideas found in Rsync. Feed a large .tar into it, and it will store duplicate regions of it only once, then compress and optionally encrypt the result. Feed another .tar file, and it will also re-use any data found in any previous backups. This way only new changes are stored, and as long as the files are not very different, the amount of storage required is very low. Any of the backup files stored previously can be read back in full at any time. The program is format-agnostic, so you can feed virtually any files to it.

The Time Zone Database (often called tz or zoneinfo) contains code and data that represent the history of local time for many representative locations around the globe. It is updated periodically to reflect changes made by political bodies to time zone boundaries, UTC offsets, and daylight-saving rules.

Any Unix-like operating system needs a C library: the library which defines the "system calls" and other basic facilities such as open, malloc, printf, exit...

The GNU C library is used as the C library in the GNU system and most systems with the Linux kernel.

Patch is a program that applies changes to files based on differences laid out as by the program "diff". The changes may be applied to one or more files depending on the contents of the diff file. It accepts several different diff formats. It may also be used to revert previously applied differences.

This package provides all the locales supported by the GNU C Library, more than 400 in total. To use them set the LOCPATH environment variable to the share/locale sub-directory of this package.

GNU Hello prints the message "Hello, world!" and then exits. It serves as an example of standard GNU coding practices. As such, it supports command-line arguments, multiple languages, and so on.

GNU Diffutils is a package containing tools for finding the differences between files. The "diff" command is used to show how two files differ, while "cmp" shows the offsets and line numbers where they differ. "diff3" allows you to compare three files. Finally, "sdiff" offers an interactive means to merge two files.

The which program finds the location of executables in PATH, with a variety of options. It is an alternative to the shell "type" built-in command.

GNU Coreutils package includes all of the basic command-line tools that are expected in a POSIX system, excluding shell. This package is the union of the GNU fileutils, sh-utils, and textutils packages. Most of these tools offer extended functionality beyond that which is outlined in the POSIX standard.

This package provides a standalone shared library version of BFD, which is otherwise distributed and installed as part of the Binutils package release.