Spdlog
Super fast C++ logging library.
Example
#include <iostream>
#include "spdlog/spdlog.h"
int main(int, char* [])
{
namespace spd = spdlog;
try
{
//Create console, multithreaded logger
auto console = spd::stdout_logger_mt("console");
console->info("Welcome to spdlog!") ;
console->info("An info message example {}..", 1);
console->info() << "Streams are supported too " << 1;
//Formatting examples
console->info("Easy padding in numbers like {:08d}", 12);
console->info("Support for int: {0:d}; hex: {0:x}; oct: {0:o}; bin: {0:b}", 42);
console->info("Support for floats {:03.2f}", 1.23456);
console->info("Positional args are {1} {0}..", "too", "supported");
console->info("{:<30}", "left aligned");
console->info("{:>30}", "right aligned");
console->info("{:^30}", "centered");
//
// Runtime log levels
//
spd::set_level(spd::level::info); //Set global log level to info
console->debug("This message shold not be displayed!");
console->set_level(spd::level::debug); // Set specific logger's log level
console->debug("Now it should..");
//
// Create a file rotating logger with 5mb size max and 3 rotated files
//
auto file_logger = spd::rotating_logger_mt("file_logger", "logs/mylogfile", 1048576 * 5, 3);
for(int i = 0; i < 10; ++i)
file_logger->info("{} * {} equals {:>10}", i, i, i*i);
//
// Create a daily logger - a new file is created every day on 2:30am
//
auto daily_logger = spd::daily_logger_mt("daily_logger", "logs/daily", 2, 30);
//
// Customize msg format for all messages
//
spd::set_pattern("*** [%H:%M:%S %z] [thread %t] %v ***");
file_logger->info("This is another message with custom format");
spd::get("console")->info("loggers can be retrieved from a global registry using the spdlog::get(logger_name) function");
//
// Compile time debug or trace macros.
// Enabled #ifdef SPDLOG_DEBUG_ON or #ifdef SPDLOG_TRACE_ON
//
SPDLOG_TRACE(console, "Enabled only #ifdef SPDLOG_TRACE_ON..{} ,{}", 1, 3.23);
SPDLOG_DEBUG(console, "Enabled only #ifdef SPDLOG_DEBUG_ON.. {} ,{}", 1, 3.23);
//
// Asynchronous logging is very fast..
// Just call spdlog::set_async_mode(q_size) and all created loggers from now on will be asynchronous..
//
size_t q_size = 1048576; //queue size must be power of 2
spdlog::set_async_mode(q_size);
auto async_file= spd::daily_logger_st("async_file_logger", "logs/async_log.txt");
async_file->info() << "This is async log.." << "Should be very fast!";
//
// syslog example. linux only..
//
#ifdef __linux__
std::string ident = "spdlog-example";
auto syslog_logger = spd::syslog_logger("syslog", ident, LOG_PID);
syslog_logger->warn("This is warning that will end up in syslog. This is Linux only!");
#endif
}
catch (const spd::spdlog_ex& ex)
{
std::cout << "Log failed: " << ex.what() << std::endl;
}
}
// Example of user defined class with operator<<
class some_class {};
std::ostream& operator<<(std::ostream& os, const some_class& c) { return os << "some_class"; }
void custom_class_example()
{
some_class c;
spdlog::get("console")->info("custom class with operator<<: {}..", c);
spdlog::get("console")->info() << "custom class with operator<<: " << c << "..";
}
Pattern flags
Pattern flags are in the form of %[flag]
and resembles strftime function. Anything that is not pattern flag will be logged as is..
flag | meaning | example |
%v | The actual text to log | "some user text" |
%t | Thread id | "1232" |
%n | Logger's name | "some logger name" |
%l | The log level of the message | "debug", "info", etc |
%L | Short log level of the message | "D", "I", etc |
%a | Abbreviated weekday name | "Thu" |
%A | Full weekday name | "Thursday" |
%b | Abbreviated month name | "Aug" |
%B | Full month name | "August" |
%c | Date and time representation | "Thu Aug 23 15:35:46 2014" |
%C | Year in 2 digits | "14" |
%Y | Year in 4 digits | "2014" |
%D or %x | Short MM/DD/YY date | "08/23/14" |
%m | Month 1-12 | "11" |
%d | Day of month 1-31 | "29" |
%H | Hours in 24 format 0-23 | "23" |
%I | Hours in 12 format 1-12 | "11" |
%M | Minutes 0-59 | "59" |
%S | Seconds 0-59 | "58" |
%e | Millisecond part of the current second 0-999 | "678" |
%f | Microsecond part of the current second 0-999999 | "056789" |
%F | Nanosecond part of the current second 0-999999999 | "256789123" |
%p | AM/PM | "AM" |
%r | 12 hour clock | "02:55:02 pm" |
%R | 24-hour HH:MM time, equivalent to %H:%M | "23:55" |
%T or %X | ISO 8601 time format (HH:MM:SS), equivalent to %H:%M:%S | "23:55:59" |
%z | ISO 8601 offset from UTC in timezone ([+/-]HH:MM) | "+02:00" |
%% | The % sign | "%" |
%+ | spdlog's default format | "[2014-31-10 23:46:59.678] [info] [mylogger] Some message" |
Local Download
- spdlog master 04b0634
-
Spdlog-04b0634.tar.gz