What's New

Everything is new! Many changes for  2.0 happened in the C layer, 
which has been almost completely rewritten. The code has been ported to 
Lua 5.0 and greatly improved.  There have also been some API changes
that made  the interface simpler and  more consistent. Here are  some of
the changes that made it into version 2.0: 

<> Major C code rewrite. Code is modular and extensible. Hopefully, other
   developers will be motivated to provide code for SSL, local domain 
   sockets, file descriptors, pipes (on Unix) and named pipes etc;

<> Everything that is exported by the library is exported inside 
   namespaces. These should be obtained with calls to the
   'require' function; 

<> Functions such as
   send/receive/timeout/close etc do not exist anymore as stand-alone
   functions. They are now only available as methods of the appropriate
   objects;

<> All functions return a non-nil value as first return value if successful.
   All functions return 'nil' followed by error message
   in case of error. This made the library much easier to use; 

<> Greatly reduced the number of times the C select is called 
   during data transfers, by calling only on failure. This might 
   improve a lot the maximum throughput;

<> TCP has been changed to become more uniform.  It's possible to first
   create a TCP object,
   then connect or bind if needed, and finally use I/O functions. 
   'socket.connect' and 'socket.bind' functions are still
   provided for simplicity; 

<> This allows for setting a timeout value before connecting;

<> And also allows binding to a local address before connecting; 

<> New 'socket.dns.gethostname' function and 'shutdown'
   method;

<> Better error messages and parameter checking;

<> Should be interrupt safe; 

<> UDP connected sockets can break association with peer by calling
   'setpeername' with address ''*'';

<> Sets returned by 'socket.select' are associative;

<> Select checks if sockets have buffered data and returns immediately; 

<> 'socket.sleep' and 'socket.time' are now part of the
   library and are supported. They used to be available only when
   LUASOCKET_DEBUG was defined, but it turns out they might be useful for
   applications;

<> 'socket.newtry' and 'socket.protect' provide a simple
   interface to exceptions that proved very in the implementation of
   high-level modules; 

<> Socket options interface has been improved. TCP objects also 
   support socket options and many new options were added.


Lots of changes in the Lua modules, too! 

<> Every module loads only the modules that it needs. There is no waste
   of memory. LuaSocket core takes only 20k of memory;

<> New MIME and LTN12 modules make all other modules much more powerful; 

<> Support for multipart messages in the SMTP module;

<> The old callback mechanism of FTP and HTTP has been replaced with LTN12 
   sources and sinks, with advantage; 

<> Common implementation for low-level FTP and SMTP;

<> FTP, HTTP, and SMTP are implemented in multiple levels in such a way 
   that users will have no problems extending the functionality to satisfy
   personal needs; 

<> SMTP knows how to perform LOGIN and PLAIN authentication.