one_loger_one_filter.cpp

This usage:

• You have one logger
• You have one filter, which can be turned on or off
• You want to format the message before it's written
• The logger has several log destinations
  • The output goes to console, debug output window, and a file called out.txt
  • Formatting - prefix each message by its index, and append newline

Optimizations:

• use a cache string (from optimize namespace), in order to make formatting the message faster

In this example, all output will be written to the console, debug window, and "out.txt" file. It will be:

[1] this is so cool 1
[2] this is so cool again 2
[3] hello, world
[4] good to be back ;) 3

#include <boost/logging/format_fwd.hpp>

#include <boost/logging/format/named_write.hpp>
typedef boost::logging::named_logger<>::type logger_type;

#define L_ BOOST_LOG_USE_LOG_IF_FILTER(g_l(), g_log_filter()->is_enabled() ) 

// Define the filters and loggers you'll use (usually in a source file)
BOOST_DEFINE_LOG_FILTER(g_log_filter, boost::logging::filter::no_ts ) 
BOOST_DEFINE_LOG(g_l, logger_type)


void one_logger_one_filter_example() {
    // formatting    : [idx] message \n
    // destinations  : console, file "out.txt" and debug window
    g_l()->writer().write("[%idx%] |\n", "cout file(out.txt) debug");
    g_l()->mark_as_initialized();

    int i = 1;
    L_ << "this is so cool " << i++;
    L_ << "this is so cool again " << i++;

    std::string hello = "hello", world = "world";
    L_ << hello << ", " << world;

    g_log_filter()->set_enabled(false);
    L_ << "this will not be written to the log";
    L_ << "this won't be written to the log";

    g_log_filter()->set_enabled(true);
    L_ << "good to be back ;) " << i++;
}




int main() {
    one_logger_one_filter_example();
}


// End of file

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Copyright John Torjo © 2007
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