Overview

logging is an erlang library, which provides the log facility. it is inspired by python logging lib. using loggging, you can control your log output style(Handler), define log entry format(Formater). you can also develop the log handler for yourself.

Usage

the below is the usage code segments First of all, let us define some macro to simplify our code. -define(DEBUG(F, D), Logger:debug(?MODULE, ?LINE, io_lib:format(F, D))). -define(INFO(F, D), Logger:info(?MODULE, ?LINE, io_lib:format(F, D))). -define(WARNING(F, D), Logger:warning(?MODULE, ?LINE, io_lib:format(F, D))). -define(ERROR(F, D), Logger:error(?MODULE, ?LINE, io_lib:format(F, D))). -define(CRITICAL(F, D), Logger:critical(?MODULE, ?LINE, io_lib:format(F, D))). -define(LOGGING(Level, F, D), Logger:log(Level, ?MODULE, ?LINE, io_lib:format(F, D))).

tty handler

% the default handler is logging_handler_tty, the default level is WARNING
{ok, _} = logging:start("tty"),
Logger = logging:get_logger("tty"),
ok = Logger:set_formatter("(universal) - (name) -(module):(lineno) - (levelname) - (message)"),
?DEBUG("logging 1", []),
?INFO("logging 1", []),
?WARNING("logging 1", []),
?ERROR("logging 1", []),
?LOGGING(25, "logging 1", []),
?LOGGING(35, "logging 1", []),
?LOGGING(200, "logging 1", []),
logging:stop(Logger:logger_name()),
ok.

file handler

Formatter = "(universal) - (name) - (levelno) (levelname) - (message)\n",
{ok, _} = logging:start("test_file", ?LEVEL_NOTSET, {logging_handler_file, "test_file.log"}, Formatter),
Logger = logging:get_logger("test_file"),

?DEBUG("logging 1", []),
?INFO("logging 1", []),
?WARNING("logging 1", []),
?ERROR("logging 1", []),
?CRITICAL("logging 1", []),
?LOGGING(100, "logging 1", []),
logging:stop(Logger:logger_name()),
ok.

rotate handler

Formatter = "(name) - (levelno) (levelname) - (message)\n",
Handler = {logging_handler_rotate, {"/tmp/test_rotate_1024_10", "my.log", 1024, 10}},
{ok, _} = logging:start("test_rotate_base", ?LEVEL_NOTSET, Handler, Formatter),
Logger = logging:get_logger("test_rotate_base"),
[begin
    ?DEBUG("logging ~b", [N]),
    ?INFO("logging ~b", [N]),
    ?WARNING("logging ~b", [N]),
    ?ERROR("logging ~b", [N]),
    ?CRITICAL("logging ~b", [N]),
    ?LOGGING(100, "logging ~b", [N])
end || N <- lists:seq(1, 100)],
logging:stop(Logger:logger_name()),
ok.

more information, please see the test/logging_SUITE.erl file.