Yii2 指定log存放的文件

 在main.php 文件里添加

'log' => [
            'traceLevel' => YII_DEBUG ? 3 : 0,
            'targets' => [
                [
                    'class' => 'yiilogFileTarget',
                    'levels' => ['error', 'warning'],
                    'logVars' => ['*'],
                ],
                [
                    'class' => 'yiilogFileTarget',
                    'categories' => ['currency'],
                    'levels' => ['error', 'warning', 'info'],
                    'logVars' => ['*'],
                    'logFile' => '@common/runtime/logs/currency.log',
                ]
            ],
        ],