Trap the process id

[Patrick Chim]

Hi all,

For example, if I run a script that will bring up the application, how can I do to capture all the processes id of the daemons which is brought up by that script ?

Many thanks,
Patrick

[Stefan Farrelly]

A properly written deamon will parent itself to PID=1 so thats not going to help you. But check anyway, with luck they will have a PPID (parent pid number) matching the process you used to start them.

Other ways to trap them are to a date command before you start the deamons, then another at the end, and note the times, then do a ps and check the start times of all processes (STIME) belonging to that userid, and you will see those that sarted with the timeframe of your date commands.

[Carlos Fernandez Riera]

If you try to get PIDs you run in background:

/tmp/prg1 &
PRG1_PID=$!

[Andrew Cowan]

Hi,

A quick-and-dirty method is just to call "grep" and then "awk" out the PID. E.g:

ps -ef | grep mydeamon | grep -v grep | awk '{print $2}'

Its not beautiful, but it does the trick. Won't solve the PPID of 1 problem though. Some deamons also create ".PID" files when they are run.

[Patrick Chim]

Hi all,

Let me take an example and state out the question clearly.
If I bring up Informix database by command oninit, it will fork several oninit processes as well. Can I capture the process id of those child processes.

informix 5182 1 28 16:49:18 ? 0:00 oninit
informix 5183 5182 0 16:49:18 ? 0:00 oninit
informix 5184 5182 76 16:49:18 ? 0:01 oninit
informix 5185 5184 0 16:49:18 ? 0:00 oninit
informix 5186 5184 0 16:49:19 ? 0:00 oninit
informix 5187 5182 0 16:49:20 ? 0:00 oninit
informix 5188 5184 0 16:49:21 ? 0:00 oninit
informix 5189 5184 0 16:49:22 ? 0:00 oninit

In this example, how can I get the process id 5182 to 5189.

Many thanks,
Patrick

[Carlos Fernandez Riera · Accepted solution]

Perhaps informix set process group, Try :

ps -fg 5182

See man ps.

[Patrick Chim]

Carlos,

It works fine. But how can I know the pid is 5182. Can I grep this pid after I issue the command ?

Thanks,
Patrick

[Carlos Fernandez Riera]

MASTER=$(ps -aef | grep oninit | awk ' $3 == 1 { print $2; exit}')

ps -fg $MASTER

?????