Overview
--------

"Logging is the act of keeping a log. In the simplest case, messages are written to a single log file.

A transaction log is a file (i.e., log) of the communications (i.e., transactions) between a system and the users of that system,[2] or a data collection method that automatically captures the type, content, or time of transactions made by a person from a terminal with that system." -- [Wikipedia](https://en.wikipedia.org/wiki/Log_file)

Example
-------

```C++
#include <memory>
#include <cstdio>
#include <cstdarg>
#include <cstdlib>
#include <restbed>

using namespace std;
using namespace restbed;

class CustomLogger : public Logger
{
    public:
        void stop( void )
        {
            return;
        }
        
        void start( const shared_ptr< const Settings >& )
        {
            return;
        }
        
        void log( const Level, const char* format, ... )
        {
            va_list arguments;
            va_start( arguments, format );
            
            vfprintf( stderr, format, arguments );
            fprintf( stderr, "\n" );
            
            va_end( arguments );
        }
        
        void log_if( bool expression, const Level level, const char* format, ... )
        {
            if ( expression )
            {
                va_list arguments;
                va_start( arguments, format );
                log( level, format, arguments );
                va_end( arguments );
            }
        }
};

void get_method_handler( const shared_ptr< Session > session )
{
    session->close( OK, "Hello, World!", { { "Content-Length", "13" } } );
}

int main( const int, const char** )
{
    auto resource = make_shared< Resource >( );
    resource->set_path( "/resource" );
    resource->set_method_handler( "GET", get_method_handler );
    
    auto settings = make_shared< Settings >( );
    settings->set_port( 1984 );
    settings->set_default_header( "Connection", "close" );
    
    Service service;
    service.publish( resource );
    service.set_logger( make_shared< CustomLogger >( ) );
    
    service.start( settings );
    
    return EXIT_SUCCESS;
}
```

Build
-----

> $ clang++ -o example example.cpp -l restbed

Execution
---------

> $ ./example
>
> $ curl -w'\n' -v -XGET 'http://localhost:1984/resource'