{

// Log levels can be loaded from argv/env using "SPDLOG_LEVEL"

load_levels_example();

spdlog::info("Welcome to spdlog version {}.{}.{} !", SPDLOG_VER_MAJOR, SPDLOG_VER_MINOR, SPDLOG_VER_PATCH);

spdlog::warn("Easy padding in numbers like {:08d}", 12);

spdlog::critical("Support for int: {0:d}; hex: {0:x}; oct: {0:o}; bin: {0:b}", 42);

spdlog::info("Support for floats {:03.2f}", 1.23456);

spdlog::info("Positional args are {1} {0}..", "too", "supported");

spdlog::info("{:>8} aligned, {:<8} aligned", "right", "left");

// Runtime log levels

spdlog::set_level(spdlog::level::info); // Set global log level to info

spdlog::debug("This message should not be displayed!");

spdlog::set_level(spdlog::level::trace); // Set specific logger's log level

spdlog::debug("This message should be displayed..");

// Customize msg format for all loggers

spdlog::set_pattern("[%H:%M:%S %z] [%^%L%$] [thread %t] %v");

spdlog::info("This an info message with custom format");

spdlog::set_pattern("%+"); // back to default format

spdlog::set_level(spdlog::level::info);

// Backtrace support

// Loggers can store in a ring buffer all messages (including debug/trace) for later inspection.

// When needed, call dump_backtrace() to see what happened:

spdlog::enable_backtrace(10); // create ring buffer with capacity of 10 messages

for (int i = 0; i < 100; i++)

{

spdlog::debug("Backtrace message {}", i); // not logged..

}

// e.g. if some error happened:

spdlog::dump_backtrace(); // log them now!

try

{

stdout_logger_example();

basic_example();

rotating_example();

daily_example();

async_example();

binary_example();

multi_sink_example();

user_defined_example();

err_handler_example();

trace_example();

custom_flags_example();

// Flush all *registered* loggers using a worker thread every 3 seconds.

// note: registered loggers *must* be thread safe for this to work correctly!

spdlog::flush_every(std::chrono::seconds(3));

// Apply some function on all registered loggers

spdlog::apply_all([&](std::shared_ptr<spdlog::logger> l) { l->info("End of example."); });

// Release all spdlog resources, and drop all loggers in the registry.

// This is optional (only mandatory if using windows + async log).

spdlog::shutdown();

}

// Exceptions will only be thrown upon failed logger or sink construction (not during logging).

catch (const spdlog::spdlog_ex &ex)

{

std::printf("Log initialization failed: %s\n", ex.what());

return 1;

}

{

// Create color multi threaded logger.

auto console = spdlog::stdout_color_mt("console");

// or for stderr:

// auto console = spdlog::stderr_color_mt("error-logger");

{

// Create basic file logger (not rotated).

auto my_logger = spdlog::basic_logger_mt("file_logger", "logs/basic-log.txt");

{

// Create a file rotating logger with 5mb size max and 3 rotated files.

auto rotating_logger = spdlog::rotating_logger_mt("some_logger_name", "logs/rotating.txt", 1048576 * 5, 3);

{

// Create a daily logger - a new file is created every day on 2:30am.

auto daily_logger = spdlog::daily_logger_mt("daily_logger", "logs/daily.txt", 2, 30);

{

// Set the log level to "info" and mylogger to to "trace":

// SPDLOG_LEVEL=info,mylogger=trace && ./example

spdlog::cfg::load_env_levels();

// or from command line:

// ./example SPDLOG_LEVEL=info,mylogger=trace

// #include "spdlog/cfg/argv.h" // for loading levels from argv

// spdlog::cfg::load_argv_levels(args, argv);

{

// Default thread pool settings can be modified *before* creating the async logger:

// spdlog::init_thread_pool(32768, 1); // queue with max 32k items 1 backing thread.

auto async_file = spdlog::basic_logger_mt<spdlog::async_factory>("async_file_logger", "logs/async_log.txt");

// alternatively:

// auto async_file = spdlog::create_async<spdlog::sinks::basic_file_sink_mt>("async_file_logger", "logs/async_log.txt");

for (int i = 1; i < 101; ++i)

{

async_file->info("Async message #{}", i);

}

{

std::vector<char> buf(80);

for (int i = 0; i < 80; i++)

{

buf.push_back(static_cast<char>(i & 0xff));

}

spdlog::info("Binary example: {}", spdlog::to_hex(buf));

spdlog::info("Another binary example:{:n}", spdlog::to_hex(std::begin(buf), std::begin(buf) + 10));

// more examples:

// logger->info("uppercase: {:X}", spdlog::to_hex(buf));

// logger->info("uppercase, no delimiters: {:Xs}", spdlog::to_hex(buf));

// logger->info("uppercase, no delimiters, no position info: {:Xsp}", spdlog::to_hex(buf));

// logger->info("hexdump style: {:a}", spdlog::to_hex(buf));

// logger->info("hexdump style, 20 chars per line {:a}", spdlog::to_hex(buf, 20));

{

// trace from default logger

SPDLOG_TRACE("Some trace message.. {} ,{}", 1, 3.23);

// debug from default logger

SPDLOG_DEBUG("Some debug message.. {} ,{}", 1, 3.23);

// trace from logger object

auto logger = spdlog::get("file_logger");

SPDLOG_LOGGER_TRACE(logger, "another trace message");

{

auto console_sink = std::make_shared<spdlog::sinks::stdout_color_sink_mt>();

console_sink->set_level(spdlog::level::warn);

console_sink->set_pattern("[multi_sink_example] [%^%l%$] %v");

auto file_sink = std::make_shared<spdlog::sinks::basic_file_sink_mt>("logs/multisink.txt", true);

file_sink->set_level(spdlog::level::trace);

spdlog::logger logger("multi_sink", {console_sink, file_sink});

logger.set_level(spdlog::level::debug);

logger.warn("this should appear in both console and file");

logger.info("this message should not appear in the console, only in the file");

{

int i;

template<typename OStream>

friend OStream &operator<<(OStream &os, const my_type &c)

{

return os << "[my_type i=" << c.i << "]";

}

{

// can be set globally or per logger(logger->set_error_handler(..))

spdlog::set_error_handler([](const std::string &msg) { printf("*** Custom log error handler: %s ***\n", msg.c_str()); });

{

std::string ident = "spdlog-example";

auto syslog_logger = spdlog::syslog_logger_mt("syslog", ident, LOG_PID);

syslog_logger->warn("This is warning that will end up in syslog.");

{

std::string tag = "spdlog-android";

auto android_logger = spdlog::android_logger_mt("android", tag);

android_logger->critical("Use \"adb shell logcat\" to view this message.");

{

void format(const spdlog::details::log_msg &, const std::tm &, spdlog::memory_buf_t &dest) override

{

std::string some_txt = "custom-flag";

dest.append(some_txt.data(), some_txt.data() + some_txt.size());

}

std::unique_ptr<custom_flag_formatter> clone() const override

{

return spdlog::details::make_unique<my_formatter_flag>();

}

{

using spdlog::details::make_unique; // for pre c++14

auto formatter = make_unique<spdlog::pattern_formatter>();

formatter->add_flag<my_formatter_flag>('*').set_pattern("[%n] [%*] [%^%l%$] %v");

spdlog::set_formatter(std::move(formatter));