How to get the trace of process?

Suppose there is a process which is in inactive state from many days and i want to know until what time the process is in active state. Other th开发者_如何学JAVAan the log records where i can get that information? This is unix platform.

Use strace debugging utility. You can attach to already running process, save output to log file and analyse it later.

[root@localhost ~]#
[root@localhost ~]# strace -o log -p 7166
Process 7166 attached - interrupt to quit