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<program name='0export'
author='Thomas Leonard'
git='http://repo.or.cz/w/0export.git'
feed='http://0install.net/tools/0export.xml'
license='GNU General Public License'>
<p>
<b>0export</b> creates self-installing bundles for distribution on CD, etc
</p>
<p>
Normally, a program is run by passing its name (a URI) to the 0launch
command. This downloads the appropriate feeds, chooses a set of
implementations (a version of the program, along with any libraries it
needs) and downloads them too.
</p>
<p>
However, it is sometimes useful to bundle a program and its libraries
together on a CD (for example) so that it can be used on machines without a
network connection, or where the network is very slow. It is also useful for
archival purposes, in case the original web-sites supplying required
libraries become unavailable.
</p>
</program>
<p>
0export takes the URI of a program and creates a "setup.sh" file; a
self-extracting archive containing everything needed to run the program.
This file can be executed on a machine without a network connection to
install or run the program.
</p>
<p>
Unlike the bundles created by the related <a href='http://roscidus.com/desktop/Zero2Bundle'>Zero2Bundle</a> program, programs
installed using setup.sh are added to the Zero Install cache and are
therefore still <a href='sharing.html'>shared between users</a>, and
will get updates over the web where possible.
</p>
<toc level='h2'/>
<h2>Using a 0export package</h2>
<p>Open the file with your file manager, or run "<b>sh setup.sh</b>" in a terminal:</p>
<p style='text-align: center'>
<img width="536" height="323" src="screens/0export-run.png" alt='Running a 0export setup file'/>
</p>
<p>The archive will unpack and run:</p>
<p style='text-align: center'>
<img width="399" height="162" src="screens/0export-unpack.png" alt='The self-extracting package unpacks itself'/>
</p>
<p>You can add the program to your menus or run it directly.</p>
<p style='text-align: center'>
<img width="399" height="162" src="screens/0export-actions.png" alt='Optional actions'/>
</p>
<h2>Current status</h2>
<p>
This program is not yet complete. In particular, adding the program to the user's menus only works if the user
already has Zero Install itself installed.
</p>
<h2>Installing 0export</h2>
<p>
You can download <b>0export</b> and create a short-cut to it in the usual way:
</p>
<pre>$ 0install add 0export http://0install.net/tools/0export.xml</pre>
<h2>Creating a setup.sh for your program</h2>
<p>
Run 0export, passing in the name of the installer file to create and the name (URI)
of the main program. For example, to create an installer for Edit:
</p>
<pre>
$ 0export setup.sh http://rox.sourceforge.net/2005/interfaces/Edit
</pre>
<p>
The resulting setup.sh file can be copied to a CD and run on another machine. This
machine does not need a network connection. It also does not need to have Zero Install
installed on it before-hand.
</p>
<p>
However, if the machine does have a network connection then the user will be notified
of updates in the usual way.
</p>
<h2>Format of the setup.sh</h2>
<p>
The bulk of the setup.sh file is an archive containing:
</p>
<ul>
<li>All feeds needed to run the program.</li>
<li>All GPG keys signing the feeds.</li>
<li>All selected implementations (versions).</li>
<li>A copy of Zero Install, in case the target system doesn't have it.</li>
<li>An installation script.</li>
</ul>
<p>
To make the archive self-extracting, a short shell script is prepended to
the archive which unpacks it to a temporary directory and then runs the
installer. If you want to extract the files without executing anything, you
can get the information you need from the first four lines of the script, which
look like this:
</p>
<pre>
#!/bin/sh
# 0export 0.1
archive_offset=00831
archive_format=application/x-bzip-compressed-tar
</pre>
<h2>Testing</h2>
<p>
To test the installer:
</p>
<pre>$ sh setup.sh</pre>
<p>
The script currently (0export 0.1) does the following:
</p>
<ol>
<li>Runs <b>gpg --import</b> on each GPG key in the archive, adding the keys that
signed the feeds to your key-ring.</li>
<li>Runs <b>0launch --import</b> on each feed in the archive. Every signing GPG key
is added to the trusted list for the feed's domain. This allows checking for updates
in future without confirming the keys. If the user already has a newer version of the
feed, the import has no effect.</li>
<li>Chooses a set of implementations (<b>0install select --xml URI</b>) in
minimal network use mode and with the implementations in the setup.sh available.</li>
<li>Copies any selected implementations into the system or user's cache (<b>~/.cache/0install.net/implementations</b>).</li>
<li>Runs the program (<b>0launch --offline URI</b>).</li>
</ol>
<p>
All steps use the bundled version of 0launch.
</p>
<h2>Support for multiple architectures or multiple applications in one bundle</h2>
<p>
You can use the "--arch" option to set the target architecture(s).
For example, this command will select two binaries for each component,
one that will run on an i586 machine and one that will run on an x86_64
machine:
</p>
<pre>0export --arch Linux-i586 --arch Linux-x86_64 setup.sh http://...</pre>
<p>
If a single binary is the best option for both then it will
only be included in the bundle once. When the bundle is installed, only
the required versions will be copied into the machine's cache.
</p>
<p>
You can include multiple applications by listing multiple URIs. All applications
will be added to the user's menu, but only the first will be run if the user selects
the run option in the dialog. Note that dependencies are included automatically and
should not be listed.
</p>
<h2>FAQ</h2>
<dl>
<dt>What about security?</dt>
<dd>Running an executable isn't a great way to install a program. The normal
Zero Install process of dragging a feed link to a trusted installation program
is much better. However, distributions have been very slow to support this.
0export is an attempt to boot-strap the adoption process. The setup.sh script is
designed to be easy to parse, so that in future it can be used as a simple archive.
</dd>
<dt>Why doesn't it confirm before trusting the keys?</dt>
<dd>
If the setup.sh is genuine then this is what you want. If it isn't, it's
already too late. Even if the normal install script asked for confirmation,
a malicious version could be modified to skip the check. One of many reasons
why install scripts are a bad idea.
</dd>
</dl>
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