Where could I find the Tikz Manual version 3.0.1a as a PDF file ?
More generally, how do I find the documentation for a package.
There are at least four ways to find the documentation of a package or class.
Both TeXLive and MikTeX provide the
texdoc command line tool which will usually find the correct documentation for a package with the following command:
For example, to find the TikZ (or pgf) manual you can just type:
If that doesn't bring up the right documentation, (it usually does) you can ask it to provide a list of possible options by entering:
texdoc -s <package-name>
This will give you a numbered list of possible documents to choose from.
If you install TeXLive, documentation for packages is included by default with a full installation.
If you install MikTeX, documentation may not be installed by default and you may need to use the package manager to install it.
Many TeX IDEs provide access to
texdoc through a menu item. This will depend on the actual editor, but looking in the Help menu is usually a place to start.
There is an online version of
texdoc that allows you to get the PDF documentation through the web directly: The URL will have the form:
So for your example:
All of the packages in TeXLive and MikTeX are hosted on https://www.ctan.org/, the Comprehensive TeX Archive Network.
As a last resort you can search there for the package and its documentation will be there too.