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| Network support for the Lua language |
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| Network support for the Lua language |
LuaSocket 2.0 uses the new package proposal for Lua 5.1. All Lua library developers are encouraged to update their libraries so that all libraries can coexist peacefully and users can benefit from the standardization and flexibility of the standard.
The proposal was considered important enough by some of us to justify early adoption, even before release of Lua 5.1. Thus, a compability module compat-5.1 has been released in conjunction with Roberto Ierusalimschy and The Kepler Project team. It implements the Lua 5.1 package proposal on top of Lua 5.0.
As far as LuaSocket is concerned, this means that whoever is deploying a non-standard distribution of LuaSocket will probably have no problems customizing it. Here we will only describe the standard distribution. If the standard doesn't meet your needs, we refer you to the Lua discussion list, where any question about the package scheme will likely already have been answered.
The standard distribution reserves a directory to be the root of the libraries installed on a given system. Let's call this directory <ROOT>. On my system, this is the /usr/local/share/lua/5.0 directory. Here is the standard LuaSocket distribution directory structure:
<ROOT>/compat-5.1.lua <ROOT>/socket.lua <ROOT>/lsocket.dll <ROOT>/mime.lua <ROOT>/lmime.dll <ROOT>/ltn12.lua <ROOT>/socket/http.lua <ROOT>/socket/tp.lua <ROOT>/socket/ftp.lua <ROOT>/socket/smtp.lua <ROOT>/socket/url.lua
Naturally, on Unix systems, lsocket.dll and lmime.dll would be replaced by lsocket.so and lmime.so. In Mac OS X, they would be replaced by lsocket.dylib and lmime.dylib.
In order for the interpreter to find all LuaSocket components, three environment variables need to be set. The first environment variable tells the interpreter to load the compat-5.1.lua module at startup:
LUA_INIT=@<ROOT>/compat-5.1.lua
The other two environment variables instruct the compatibility module to look for dynamic libraries and extension modules in the appropriate directories and with the appropriate filename extensions.
LUA_PATH=<ROOT>/?.lua;?.lua LUA_CPATH=<ROOT>/?.dll;?.dll
Again, naturally, in Unix the shared library extension would be .so instead of .dll and on Mac OS X it would be .dylib
With the above setup, and an interpreter with shared library support, it should be easy to use LuaSocket. Just fire the interpreter and use the require function to gain access to whatever module you need:
Lua 5.0.2 Copyright (C) 1994-2004 Tecgraf, PUC-Rio
> socket = require("socket")
> print(socket.VERSION)
--> LuaSocket 2.0 (beta3)
Each module loads their dependencies automatically, so you only need to load the modues you directly depend upon:
Lua 5.0.2 Copyright (C) 1994-2004 Tecgraf, PUC-Rio
> http = require("socket.http")
> print(http.request("http://www.tecgraf.puc-rio.br/luasocket"))
--> homepage gets dumped to terminal