On Saturday, 30 May 2020 at 18:17:21 UTC, mw wrote:
A related question: how to log to multiple destinations? e.g.
both console & log file? any examples?
Thanks.
```D
auto multiLogger = new MultiLogger();
multiLogger.insertLogger("console", new FileLogger(stdout,
LogLevel.all));
multiLogger.insertLogger("file", new FileLogger(outputFile,
LogLevel.all));
sharedLog = multiLogger;
```
If you are missing color output for log level , you can use this
ConsoleLogger
```D
import std.experimental.logger;
/// Extends FileLogger to log only to stdout and colorize log
level
class ConsoleLogger : FileLogger
{
import std.concurrency : Tid;
import std.datetime.systime : SysTime;
import std.format : formattedWrite;
this(const LogLevel lv = LogLevel.all)
{
import std.stdio : stdout;
super(stdout, lv);
}
/* This method overrides the base class method in order to
log to a file
without requiring heap allocated memory. Additionally, the
`FileLogger`
local mutex is logged to serialize the log calls.
*/
override protected void beginLogMsg(string file, int line,
string funcName,
string prettyFuncName, string moduleName, LogLevel logLevel,
Tid threadId, SysTime timestamp, Logger logger)
@safe
{
import std.string : lastIndexOf;
ptrdiff_t fnIdx = file.lastIndexOf('/') + 1;
ptrdiff_t funIdx = funcName.lastIndexOf('.') + 1;
auto lt = this.file_.lockingTextWriter();
systimeToISOString(lt, timestamp);
colorizeLogLevel(lt, logLevel);
formattedWrite(lt, " %s:%u:%s ", file[fnIdx .. $], line,
funcName[funIdx .. $]);
}
private void colorizeLogLevel(Writer)(auto ref Writer lt,
LogLevel logLevel) @safe
{
import std.conv : to;
auto logLevelStr = logLevel.to!string;
switch (logLevel) {
case LogLevel.all:
formattedWrite(lt, " [\033[1;37;40m%s\033[0m] ",
logLevelStr);
break;
case LogLevel.trace:
formattedWrite(lt, " [\033[1;37;40m%s\033[0m] ",
logLevelStr);
break;
case LogLevel.info:
formattedWrite(lt, " [\033[1;32;40m%s\033[0m] ",
logLevelStr);
break;
case LogLevel.warning:
formattedWrite(lt, " [\033[1;33;40m%s\033[0m] ",
logLevelStr);
break;
case LogLevel.error:
formattedWrite(lt, " [\033[1;31;40m%s\033[0m] ",
logLevelStr);
break;
case LogLevel.critical:
formattedWrite(lt, " [\033[1;37;41m%s\033[0m]",
logLevelStr);
break;
case LogLevel.fatal:
formattedWrite(lt, " [\033[1;25;37;41m%s\033[0m] ",
logLevelStr);
break;
default:
formattedWrite(lt, " [\033[1;37;40m%s\033[0m] ",
logLevelStr);
}
}
}
```
