zsync
Partial differential file downloader over HTTP
TLDR
Download a file using a .zsync URL
$ zsync [http://example.com/path/to/file.zsync]
Use a local file as seed for differential download$ zsync -i [path/to/existing_file] [http://example.com/path/to/file.zsync]
Save downloaded file with a specific name$ zsync -o [path/to/output_file] [http://example.com/path/to/file.zsync]
Save the .zsync file locally for future conditional requests$ zsync -k [path/to/saved.zsync] [http://example.com/path/to/file.zsync]
Download in quiet mode without progress bar$ zsync -q [http://example.com/path/to/file.zsync]
Authenticate with a server$ zsync -A [hostname]=[user]:[password] [http://hostname/path/to/file.zsync]
SYNOPSIS
zsync [OPTIONS] URL
DESCRIPTION
zsync is a partial/differential file downloader. It downloads only the changed parts of files using .zsync control files, similar to rsync but over HTTP.Useful for updating large files like ISO images when only small parts have changed.
PARAMETERS
-i FILE
Use local file as seed for differential download. Can be specified multiple times.-o FILE
Save downloaded file with specified name instead of the default-k FILE
Save the downloaded .zsync file with the given filename. If the file already exists, makes a conditional request to only download if the server's copy is newer.-q
Quiet mode, suppress progress bar, download rate, and ETA display-s
Deprecated synonym for -q-u URL
Specify referring URL. Required when using a local .zsync file that contains relative URLs.-A hostname=username:password
Provide authentication credentials for the given hostname. Can be used multiple times for different servers.-V
Print version information
INSTALL
sudo apt install zsync
sudo dnf install zsync
sudo pacman -S zsync
sudo zypper install zsync
brew install zsync
nix profile install nixpkgs#zsync
CAVEATS
Requires a .zsync control file generated on the server side. The server must support HTTP range requests. HTTPS support depends on the build.