Android 代码实现logcat输出到文件

Android 的logcat支持直接输出到文件。

关键代码：

Runtime.getRuntime().exec("logcat -f "+ filePath);

我个人习惯是写在application的 oncreate()中。

logcat还支持很多其他参数，具体可以参见官方文档。

http://developer.android.com/tools/debugging/debugging-log.html#startingLogcat

这个方法不需要权限，但是对于其他应用的log,是打不出来的。

这是官方说明：

The change is that third party applications can no longer get the read logs permission, however every app can read the logs containing only the lines they have written, without needing any permission.

Keep in mind that access to the logs has never been part of the SDK, and is still not part of the SDK. If you are relying on it then, even after this change, you run the risk of breaking in the future. (And that is partly why this got lost for documentation,
it is not part of the SDK, so there isn't really a place to document it, in fact documenting it would kind-of make it a part of the SDK which we don't want. :p)