Lua-iconv: performs character set conversions in Lua
       (c) 2005 Alexandre Erwin Ittner <aittner@netuno.com.br>
              Project page: http://lua-iconv.luaforge.net/




=== INTRODUCTION ===

Lua-iconv is a Lua binding to the POSIX 'iconv' library. The iconv
library converts the sequence of characters from one codeset, into a
sequence of corresponding characters in another codeset. The codesets
are those specified in the iconv.new() call that returned the conversion
descriptor, cd.

Details regarding iconv may be obtained from:
http://www.opengroup.org/onlinepubs/007908799/xsh/iconv.h.html



=== LICENSE ===

Lua-iconv is (c) 2005 Alexandre Erwin Ittner <aittner@netuno.com.br>

Lua-iconv is copyrighted free software: it can be used for both academic
and commercial purposes at absolutely no cost. There are no royalties
or GNU-like "copyleft" restrictions. The legal details are below:

   Permission is hereby granted, free of charge, to any person obtaining
   a copy of this software and associated documentation files (the
   "Software"), to deal in the Software without restriction, including
   without limitation the rights to use, copy, modify, merge, publish,
   distribute, sublicense, and/or sell copies of the Software, and to
   permit persons to whom the Software is furnished to do so, subject
   to the following conditions:

   The above copyright notice and this permission notice shall be
   included in all copies or substantial portions of the Software.

   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
   IN NO EVENT SHALL THE AUTHOR OR COPYRIGHT HOLDER BE LIABLE FOR ANY
   CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
   TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
   SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

   If you use this package in a product, an acknowledgment in the product
   documentation would be greatly appreciated (but it is not required).



=== DOWNLOAD AND INSTALLATION ===

Lua-iconv can be obtained from its Luaforge project page:
http://lua-iconv.luaforge.net/

Lua-iconv must be compiled as a shared object and loaded by the Lua
interpreter using the 'loadlib' facility (or the new module system in
Lua 5.1). To compile the library, just fire up your favourite shell, untar
the distribution package and type, as root, within the program directory:

    make install

The library will be compiled and installed on the /usr/lib/ directory.

To install the library with Lua 5.1 and above just type

    make install51

This will cause the Makefile to run a Lua script that will install the
library into a directory from package.cpath, allowing you to use the
package system to load the library.



=== LOADING AND INITIALIZATION ===

Lua-iconv is a shared library that exports a single function called
luaopen_iconv that must be called by the Lua interpreter. You must
use loadlib function to for that. Using Lua 5.0, under Unix and with
libluaiconv.so on your LUA_PATH (or also your LD_PATH) you can just do:

    assert(loadlib("libluaiconv.so", "luaopen_iconv"))()

And, under Windows and with libluaiconv.dll on your path, you can do

    assert(loadlib("libluaiconv.dll", "luaopen_iconv"))()

On the Lua 5.1, Lua-iconv uses the new package system that allows you
to simply do a

    require "gd"

call to load up the library (that was installed on the right place by
install51.lua).



=== USAGE ===

cd = iconv.new(to, from)
cd = iconv.open(to, from)

    Opens a new conversion descriptor, from the 'from' charset to the
    'to' charset. Concatenating "//TRANSLIT" to the first argument will
    enable character transliteration and concatenating "//IGNORE" to
    the first argument will cause iconv to ignore any invalid characters
    found in the input string.

    This function returns a new converter or nil on error.


nstr, err = cd:iconv(str)

    Converts the 'str' string to the desired charset. This method always
    returns two arguments: the converted string and an error code, which
    may have any of the following values:

    nil
        No error. Conversion was succeful.

    iconv.ERROR_NO_MEMORY
        Failed to allocate enough memory in the conversion process.

    iconv.ERROR_INVALID
        An invalid character was found in the input sequence.

    iconv.ERROR_INCOMPLETE
        An incomplete character was found in the input sequence.
        
    iconv.ERROR_UNKNOWN
        There was an unknown error.