yesterday

linux下查看系统工具原码,如IOSTAT等

The sa2 shell script uses a daily data file to create a daily report.
Answer n if you want it to use current daily data file (that is to say
the daily data file created today).
Yet it may be sometimes useful to tell it to use the daily data file
of the day before (that is to say the one created yesterday), for
example if sa2 is started at, say, 02:00 AM. In this case, answer y.