linkchecker/doc/install.txt

Installation
============
If you are upgrading from older versions of LinkChecker you should
also read the upgrading documentation stored in upgrading.txt.

When installing from source, for application translations to be installed
polib_ needs to be installed before LinkChecker. After LinkChecker installation
polib_ can be removed.

Installing from the GitHub release assets requires setuptools-scm-git-archive_.

pip-run_ may be useful for both of these cases.

There are several steps to resolve problems with detecting the character
encoding of checked HTML pages:
first ensure the web server, if used, is not returning an incorrect charset in
the Content-Type header; second, if possible add a meta element to the HTML
page with the correct charset; finally, install cchardet_ - Beautiful Soup has
its own encoding detector but will use in order of preference cchardet_ or
chardet_. You might find that one of the other three detectors works better for
your pages. There may already be a system copy of e.g. chardet installed;
installing LinkChecker in a Python venv_ gives control over which packages are
used.

.. _chardet: https://pypi.org/project/chardet/

.. _pip-run: https://pypi.org/project/pip-run/

.. _cchardet: https://pypi.org/project/cchardet/

.. _polib: https://pypi.org/project/polib/

.. _setuptools-scm-git-archive: https://pypi.org/project/setuptools-scm-git-archive/

.. _venv: https://docs.python.org/3/library/venv.html#creating-virtual-environments

Setup with pip
------------------
pip_ can be used to install LinkChecker on the local system.

If you want application translations, first:
``pip3 install polib``

Then this command will install LinkChecker from the latest source:
``pip3 install git+https://github.com/linkchecker/linkchecker.git``

.. _pip: https://pypi.org/project/pip/

Setup for Windows
-----------------
Python from the Microsoft Store does include pip_, but installing
within Windows Subsystem for Linux (WSL) is the preferred option:
https://docs.microsoft.com/en-us/windows/python/beginners

Setup for macOS
------------------
Python from Homebrew includes pip_. Otherwise ``get-pip.py`` can be used to
install pip_ (untested):
https://pip.pypa.io/en/stable/installation/

Setup for GNU/Linux
-------------------
On all major Linux distributions (Debian, Mandriva, Redhat, Suse, Ubuntu),
the ``linkchecker`` package is available for installation. pip_ will be
available, often as a package e.g. ``python3-pip``, to install the latest
LinkChecker.

Manual setup for Unix systems
-----------------------------
First, install the required software.

1. Python >= 3.6 from https://www.python.org/

   Be sure to also have installed the included distutils module.
   On most distributions, the distutils module is included in
   an extra ``python-dev`` package.

2. Python requests package from https://pypi.org/project/requests/

3. Python Beautiful Soup package from https://pypi.org/project/beautifulsoup4/

4. *Optional, installation time only, for translations:*
   polib Python module from https://pypi.org/project/polib/

5. *Optional, for bash-completion:*
   argcomplete Python module from https://pypi.org/project/argcomplete/

6. *Optional, for displaying country codes:*
   GeoIP from https://pypi.org/project/GeoIP/

7. *Optional, used for Virus checking:*
   ClamAv from https://www.clamav.net/

8. *Optional, to run the WSGI web interface:*
   Apache from https://httpd.apache.org/
   mod_wsgi from https://pypi.org/project/mod-wsgi/

Note for developers: if you want to regenerate the po/linkchecker.pot template
from the source files, you will need xgettext with Python support. This is
available in gettext >= 0.12.

Now install the application.

1. Compile Python modules
   
   Run ``python setup.py sdist --manifest-only`` to create the MANIFEST
   file.
   Run ``python setup.py build`` to compile the Python files.
   For help about the setup.py script options, run
   ``python setup.py --help``.

2.
   a) Installation as root
      
      Run ``sudo python setup.py install`` to install LinkChecker.
   
   b) Installation as a normal user
      
      Run ``python setup.py install --home $HOME``. Note that you have
      to adjust your PATH and PYTHONPATH environment variables, eg. by
      adding the commands ``export PYTHONPATH=$HOME/lib/python`` and
      ``export PATH=$PATH:$HOME/bin`` to your shell configuration
      file.
      
      For more information look at the `Modifying Python's search path`_
      documentation.
      
      .. _Modifying Python's search path:
         https://docs.python.org/3/install/#inst-search-path


After installation
------------------
LinkChecker is now installed. Have fun!


WSGI web interface
-----------------------
The included WSGI script can run LinkChecker with a nice graphical web
interface.
You can use and adjust the example HTML files in the lconline directory
to run the script.

1. Note that running LinkChecker requires CPU and memory resources.
   Allowing a WSGI script to execute such a program for possibly a
   large number of users might deplete those resources.
   Be sure to only allow access from trusted sites to this script.
   
2. Copy the script lc.wsgi in the WSGI directory.

3. Adjust the "action=..." parameter in lconline/lc_cgi.html
   to point to your WSGI script.

4. If you use Apache, copy config/linkchecker.apache2.conf
   into your Apache configuration directory (eg. /etc/apache2/conf.d)
   and enable it.

5. Load the lconline/index.html file, enter an URL and click on the
   check button.

6. If something goes wrong, check the following:
   
   a) look in the error log of your web server
   b) be sure that you have enabled WSGI support in your web server,
      for example by installing mod_wsgi for Apache
   c) be sure that you have enabled the negotiation and versioning
      modules for Apache:
      a2enmod version
      a2enmod negotiation