log库spdlog简介及使用
spdlog是一个开源的、快速的、仅有头文件的C++11 日志库,code地址在 https://github.com/gabime/spdlog?,目前最新的发布版本为0.14.0。它提供了向流、标准输出、文件、系统日志、调试器等目标输出日志的能力。它支持的平台包括Windows、Linux、Mac、Android。 spdlog特性: (1)、非常快,性能是它的主要目标; (2)、仅包括头文件; (3)、日志的格式化处理使用开源的fmt库( ?https://github.com/fmtlib/fmt ); (4)、可选的printf语法支持; (5)、非常快的异步模式(可选),支持异步写日志; (6)、自定义格式; (7)、条件日志; (8)、多线程/单线程日志; (9)、各种日志目标:可对日志文件进行循环输出;可每日生成日志文件;支持控制台日志输出(支持颜色);系统日志;Windows debugger;较容易扩展自定义日志目标; (10)、支持日志输出级别:阈值级别既可以在运行时也可以在编译时修改。 以下是测试代码,主要来自spdlog/example/example.cpp: ? #include "funset.hpp"
#include <iostream>
#include "spdlog/spdlog.h"
#include "spdlog/fmt/ostr.h"
namespace spd = spdlog;
int test_spdlog_console() {
try {
// Console logger with color
auto console = spd::stdout_color_mt("console");
console->info("Welcome to spdlog!");
console->error("Some error message with arg{}..",1);
// Conditional logging example
console->info_if(true,"Welcome to spdlog conditional logging!");
// Formatting examples
console->warn("Easy padding in numbers like {:08d}",12);
console->critical("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");
SPDLOG_DEBUG_IF(console,true,"This is a debug log");
spd::get("console")->info("loggers can be retrieved from a global registry using the spdlog::get(logger_name) function");
// Create basic file logger (not rotated)
auto my_logger = spd::basic_logger_mt("basic_logger","E:/GitCode/Messy_Test/testdata/basic_log");
my_logger->info("Some log message");
// Create a file rotating logger with 5mb size max and 3 rotated files
auto rotating_logger = spd::rotating_logger_mt("some_logger_name","E:/GitCode/Messy_Test/testdata/mylogfile_log",1048576 * 5,3);
for (int i = 0; i < 10; ++i)
rotating_logger->info("{} * {} equals {:>10}",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","E:/GitCode/Messy_Test/testdata/daily_log",2,30);
// trigger flush if the log severity is error or higher
daily_logger->flush_on(spd::level::err);
daily_logger->info(123.44);
// Customize msg format for all messages
spd::set_pattern("*** [%H:%M:%S %z] [thread %t] %v ***");
rotating_logger->info("This is another message with custom format");
// 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("This message shold be displayed..");
// Compile time log levels
// define SPDLOG_DEBUG_ON or SPDLOG_TRACE_ON
SPDLOG_TRACE(console,"Enabled only #ifdef SPDLOG_TRACE_ON..{},{}",1,3.23);
SPDLOG_DEBUG(console,"Enabled only #ifdef SPDLOG_DEBUG_ON.. {},3.23);
SPDLOG_DEBUG_IF(console,"This is a debug log");
// Apply a function on all registered loggers
spd::apply_all([&](std::shared_ptr<spdlog::logger> l) { l->info("End of example."); });
// Release and close all loggers
spdlog::drop_all();
}
// Exceptions will only be thrown upon failed logger or sink construction (not during logging)
catch (const spd::spdlog_ex& ex) {
std::cout << "Log init failed: " << ex.what() << std::endl;
return -1;
}
return 0;
}
int test_spdlog_async() {
// 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 = 4096; //queue size must be power of 2
spdlog::set_async_mode(q_size);
auto async_file = spd::daily_logger_st("async_file_logger","E:/GitCode/Messy_Test/testdata/async_log");
for (int i = 0; i < 100; ++i)
async_file->info("Async message #{}",i);
return 0;
}
int test_spdlog_syslog() {
// there is no syslog.h file in windows,so macro SPDLOG_ENABLE_SYSLOG should be disenable
#ifdef SPDLOG_ENABLE_SYSLOG
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.");
#endif
return 0;
}
// user defined types logging by implementing operator<<
struct my_type {
int i;
template<typename OStream>
friend OStream& operator<<(OStream& os,const my_type& c)
{
return os << "[my_type i=" << c.i << "]";
}
};
int test_spdlog_user_defined() {
try {
//spd::get("console")->info("user defined type: {}",my_type{ 14 });
auto console = spd::stdout_color_mt("console");
console->info("user defined type: {}",my_type{ 14 });
} catch (const spd::spdlog_ex& ex) {
std::cout << "user defined log fail: " << ex.what() << std::endl;
return -1;
}
return 0;
}
int test_spdlog_err_handler() {
// can be set globaly or per logger(logger->set_error_handler(..))
spdlog::set_error_handler([](const std::string& msg)
{
std::cerr << "my err handler: " << msg << std::endl;
});
//spd::get("console")->info("some invalid message to trigger an error {}{}{}{}",3);
auto console = spd::stdout_color_mt("console");
console->info("some invalid message to trigger an error {}{}{}{}",3);
return 0;
} 执行结果如下:
? GitHub:?https://github.com/fengbingchun/Messy_Test 再分享一下我老师大神的人工智能教程吧。零基础!通俗易懂!风趣幽默!还带黄段子!希望你也加入到我们人工智能的队伍中来!https://blog.csdn.net/jiangjunshow (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |
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