Log command outputs

Log command outputs for later analysis, turned off by default.

To turn it on, using options as:

$ options save-result true
 NAME         BEFORE-VALUE  AFTER-VALUE
----------------------------------------
 save-result  false         true
Affect(row-cnt:1) cost in 3 ms.

F.Y.I

  1. logging file lies in: {user.home}/logs/arthas-cache/result.log;
  2. remember to clean up the file to save disk space.

Asynchronous log

:notes: :notes: With the latest Arthas, you can log the outputs asynchronously in the background:

$ trace Test t >>  &
job id  : 2
cache location  : /Users/zhuyong/logs/arthas-cache/28198/2

F.Y.I

  1. quit/exit or Ctrl+C will not affect the asynchronous jobs :sparkles:;
  2. default timeout for the background job is 1 day (you can set it via options);
  3. outputs will be save to the cache location now (no matter what save-result is - not ~/logs/arthas-cache/result.log any more).