How to calculate the length of process's life in Linux?

cypkw · 11-15-2010, 07:18 AM

Hi everybody.
I would like to ask you some questions about the length of process's life.
Each process has its life length.From its being created to end.
The length of each process's life may not be different.
If i want to calculate the process's life length in linux,what should i do?
please give me some advices.
thank you for your reading.

stress_junkie · 11-15-2010, 10:06 AM

You need to know specifically which process you want to analyze. For example the init process runs the entire time that Linux is running. On the other hand when you execute a command Linux spawns child a process that only lasts as long as it takes to finish executing the command.

If you want to analyze processes at random then you can enable Linux process accounting. That will keep details about all of the processes that run on the computer. You can then analyze any process that has already run.

psisquare · 11-15-2010, 12:46 PM

Maybe you're searching for time(1) (try "man 1 time")?

Code:

$ time ping -c1 linuxquestions.org > /dev/null

real    0m0.493s
user    0m0.000s
sys     0m0.007s

ravi.xolve · 11-17-2010, 12:26 AM

This command:

ps -e

in the third column gives the time for the process.