Adding a page on setting up a Lua programming environment on tilde.team.

wiki/pages/lua.md

@@ -0,0 +1,51 @@
+author: ~evn
+published: false
+title: lua
+category:
+    - main
+---
+
+# Lua
+
+This page will explain how to set up your tilde.team account for 
+[Lua](https://www.lua.org/) programming. 
+
+## Luarocks
+
+[Luarocks](https://luarocks.org/) is a package manager for the Lua, similar to
+Python's PIP, Perl's PPM, and other programming laguages' package mangers. To
+download and install a package from the Luarocks repository type the following
+into a terminal: 
+    `luarocks install [package-name] --local`
+where [package-name]
+is the name of the package you want to install (without square brackets). The
+'--local' argument is necessary to install the package to your user folder
+rather than the default path of '/usr/local/', which tilde.team users do not
+have write access to.  
+
+Lua uses the environment variables 'LUA_PATH' and 'LUA_CPATH' to find installed
+packages. By default these paths do not include the paths that Luarocks installs
+package to, so the Lua interpreter will not be able to find installed packages.
+The `luarocks path` command can be used to modify the LUA_PATH and LUA_CPATH 
+environment variables to include the paths that Luarocks installs packages to.
+The following command will modify the environment variables appropriately:
+    `eval $(luarocks path --bin)`
+Add this to your ~/.bashrc file to make these environment variables always
+include the necessary paths.
+
+The version of Luarocks installed on tilde.team is configured for use with Lua 
+version 5.1, so packages installed with Luarocks will not be usable with lua
+5.2.  
+
+## Lua Versions
+
+Tilde.team has two versions of the Lua interpreter installed; version 5.1 and
+version 5.2. When you type `lua` into a terminal it will run version 5.2 by
+default. To run Lua version 5.1 simply type `lua5.1`.  
+
+To set the default Lua interpreter to version 5.1 set a bash alias with the 
+following command:
+    `alias lua="/usr/bin/lua5.1"`
+Add this to your ~/.bashrc file to always use version 5.1 as the default Lua
+interpreter.
+