index.js
function writeLog(level, msg) {
  var line;
  if(showSourceInfo) {
    var si = getSourceInfo();
    if (includeDate) {
      line = util.format("[%s] <%s>\t[%s:%s] %s", moment().format(), level, si.file, si.lineNumber, msg);
    } else {
      line = util.format("<%s>\t[%s:%s] %s", level, si.file, si.lineNumber, msg);
    }
  } else {
    if (includeDate) {
      line = util.format("[%s] <%s>\t%s", moment().format(), level, msg);
    } else {
      line = util.format("<%s>\t%s", level, msg);
    }
  }

  line += '\n';
  appenders.forEach(function(appender) {
    appender(level, line);
  });
}
function writeLog(level, msg) {
  var line;
  if(showSourceInfo) {
    var si = getSourceInfo();
    if (includeDate) {
      line = util.format("[%s] <%s>\t[%s:%s] %s", moment().format(), level, si.file, si.lineNumber, msg);
    } else {
      line = util.format("<%s>\t[%s:%s] %s", level, si.file, si.lineNumber, msg);
    }
  } else {
    if (includeDate) {
      line = util.format("[%s] <%s>\t%s", moment().format(), level, msg);
    } else {
      line = util.format("<%s>\t%s", level, msg);
    }
  }

  line += '\n';
  appenders.forEach(function(appender) {
    appender(level, line);
  });
}
function writeLog ( level , msg ) { var line ; if ( showSourceInfo ) { var si = getSourceInfo ( ) ; if ( includeDate ) { line = util . format ( "[%s] <%s>\t[%s:%s] %s" , moment ( ) . format ( ) , level , si . file , si . lineNumber , msg ) ; } else { line = util . format ( "<%s>\t[%s:%s] %s" , level , si . file , si . lineNumber , msg ) ; } } else { if ( includeDate ) { line = util . format ( "[%s] <%s>\t%s" , moment ( ) . format ( ) , level , msg ) ; } else { line = util . format ( "<%s>\t%s" , level , msg ) ; } } line += '\n' ; appenders . forEach ( function ( appender ) { appender ( level , line ) ; } ) ; }
Writes the log to stderr

Partially based on clim (http://github.com/epeli/node-clim)
Copyright (c) 2009-2011 Esa-Matti Suuronen <esa-matti@suuronen.org>
Writes the log to stderr