Ubuntu PID question

grigory · 01-11-2016, 11:44 PM

Hello!

I need some explanation as to why in Ubuntu the Process ID (PID) differs when it's being checked in different ways.
For example, crond. When I do this:

Quote:

sudo service cron status

I get:

Quote:

cron start/running, process 5610

But when I do that:

Quote:

ps aux | grep crond

I get:

Quote:

myusername 5647 0.0 0.0 17164 2412 pts/11 S+ 08:12 0:00 grep --color=auto crond

And when I run this command again and again I'm getting different PID each time (first 2 digits remain the same though, like 56xx).

Quote:

myusername 5658 0.0 0.0 17164 2400 pts/11 S+ 08:13 0:00 grep --color=auto crond

astrogeek · 01-11-2016, 11:51 PM

The last two are not the PID of crond, they are the PIDs of your grep command...

Code:

myusername 5647 0.0 0.0 17164 2412 pts/11 S+ 08:12 0:00 grep --color=auto crond

myusername 5658 0.0 0.0 17164 2400 pts/11 S+ 08:13 0:00 grep --color=auto crond

grigory · 01-12-2016, 04:44 AM

Thanks!

I ran this command this time:

Code:

ps aux | grep cron

And I got the same PID in both cases.