Partial/differential file download client over HTTP(S).

Downloads a file over HTTP(S). zsync uses a control file to determine whether any blocks in the file are already known to the downloader, and only downloads the new blocks.

This fork uses libcurl in order to support HTTPS and is mirrored from Launchpad. It has been further modified to respond more gracefully to redirects.

To build and install locally:

sudo apt-get -y install git devscripts autotools-dev libcurl4-openssl-dev
git clone https://github.com/probonopd/zsync-curl.git
./zsync-curl/build.sh

To build a deb:

sudo apt-get -y install autotools-dev libcurl4-openssl-dev git debhelper
git clone https://github.com/probonopd/zsync-curl.git
cd ./zsync-curl/src
debuild -i -us -uc -b
cd -

To download:

zsync_curl https://bintray.com/artifact/download/probono/AppImages/Leafpad-0.8.17-x86_64.AppImage.zsync

To download using a pre-existing seed file (e.g., older version of the same file):

zsync_curl https://bintray.com/artifact/download/probono/AppImages/Scribus-1.5.1.svn.20620-x86_64.AppImage.zsync -i Scribus-1.5.1.svn.20616-x86_64.AppImage

In this example, 94% of the data can be taken from the existing local file, and only 6% need to be downloaded.