# Lua-iconv

Perform character set conversions in Lua

(c) 2005-11 Alexandre Erwin Ittner <alexandre@ittner.com.br>


## Introduction

Lua-iconv provides POSIX 'iconv' bindings for the Lua Programming Language.
The iconv library converts a 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`.

Lua-iconv 7 *requires* Lua 5.1 or Lua 5.2. For Lua 5.0, use the first release (lua-iconv-r1).

Details on iconv may be obtained in the [Open Group's interface definition](http://www.opengroup.org/onlinepubs/007908799/xsh/iconv.h.html).


## Download and installation

Lua-iconv can be obtained from [its GitHub project page](https://github.com/lunarmodules/lua-iconv), from a LuaRocks server, or from some Linux distributions which already provide it (eg. Debian).

Unless you downloaded a compiled package, you must build the library for your system.
If you have LuaRocks installed, all the process is automatic; just fire up your favourite shell and type, as root:

```console
luarocks install lua-iconv
```

and the package will be downloaded from a rock server, installed and configured.
Otherwise, you must compile and install the package.
In a system with pkg-config (as many Linux distributions and Unix flavors) open a shell, untar the distribution package and, within the program directory, type:

```console
make install
```

as root.
The library will be compiled and installed on the in the correct path (which is defined in lua5.x.pc).
Compiling on systems without pkg-config requires manual changes in the Makefile (this includes Windows).


## Loading and initialization

Lua-iconv is a shared library that must be loaded in the Lua interpreter before use.
You can simply do a

```lua
local iconv = require("iconv")
```

call to load up the library (that, of course, must be installed in a directory from `package.cpath`).


## API documentation

```lua
cd, err = iconv.new(to, from)
cd, err = 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.

The error code, may have any of the following values:

* `nil`

    No error. Creation was successful.

* `iconv.ERROR_INVALID`

    The conversion from `from` to `to` is not supported by the implementation.

* `iconv.ERROR_UNKNOWN`

    There was an unknown error.


This function returns a new converter or nil+err on error.


```lua
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 successful.

* `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_FINALIZED`

    Trying to use an already-finalized converter. This usually means
    that the user was tweaking the garbage collector private methods.

* `iconv.ERROR_UNKNOWN`

    There was an unknown error.


## License

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:

   Lua-iconv is (c) 2005-11 Alexandre Erwin Ittner

   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).