File syncing with unison

Command Line – unison

© Photo by pan xiaozhen on Unsplash

© Photo by pan xiaozhen on Unsplash

Article from Issue 221/2019
Author(s):

Unison is a handy tool for file syncing, backups, and merging. To get the most out of unison, however, you need to invest time perfecting your preference files to meet your needs.

Although unison has been around for years, chances are you have never heard of unison. For one thing, rsync and ssh tend to be the default commands for file syncing. For another, unison's documentation is maddeningly incomplete. In the absence of man or info files or usage instructions from the creators, the existing help focuses on building a command to use at the prompt – and, considering that unison has 88 options, that is not a very attractive option, even without a command history, especially if you have several sets of files with which you regularly work. So far as I can see, the only distribution that mentions how to simplify the use of unison with preference files is Arch Linux, and even it is incomplete – as is the original documentation that Arch references. Yet once preference files are created, the number of on-the-fly options is greatly reduced, and unison becomes a handy tool for file syncing, backups, and even merging files.

unison is a shell for the rsync protocol; it also calls upon external programs like ssh and diff for its operations. It works with two sets of directories and files, updating one so that the two sets match. Its only drawback is that, if you are syncing in separate machines, each must have the same version of unison installed. The basic command structure is:

unison PATH1 PATH2

[...]

Use Express-Checkout link below to read the full article (PDF).

Buy this article as PDF

Express-Checkout as PDF
Price $2.95
(incl. VAT)

Buy Linux Magazine

SINGLE ISSUES
 
SUBSCRIPTIONS
 
TABLET & SMARTPHONE APPS
Get it on Google Play

US / Canada

Get it on Google Play

UK / Australia

Related content

  • Unison

    Unison and SSH help you sync your directories across multiple computers.

  • Conduit and Unison

    Find out how the Conduit and Unison utilities can keep your documents and files in sync on multiple computers.

  • Charly's Column

    Charly may be a traditionalist with sync-unfriendly duplicate home directories, but a little utility called Unison helps keep his data consistent . This month you’ll learn why Rsync sometimes isn’t enough.

  • Shredder_9_Chess_Too..>

    Rsync lets you synchronize your data – on either a local or remote computer. You can even use Rsync with SSH to encrypt your data.

  • Backup Solutions

    Backup strategies in IT are essential and expensive in terms of planning and administration, but individuals have simpler solutions. We look at five backup solutions for the desktop.

comments powered by Disqus
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters

Support Our Work

Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.

Learn More

News