topic Re: #ps -ef | grep pmon in Operating System - HP-UX

#ps -ef | grep pmon

Jacques Carriere — Mon, 10 Jul 2006 09:44:38 GMT

Does anyone know how to use the grep and not have the grep command listed in your selection.

Re: #ps -ef | grep pmon

Steven E. Protter — Mon, 10 Jul 2006 09:46:47 GMT

Shalom,

modify to

ps -ef | grep pmon | grep -v pmon

Even more accurate

UNIX95=1
ps -C pmon

Do not set UNIX95 permenent, it breaks sd/ux

SEP

Re: #ps -ef | grep pmon

spex — Mon, 10 Jul 2006 09:48:20 GMT

Jacques,

ps -ef | grep pmon | grep -v grep

PCS

Re: #ps -ef | grep pmon

Jacques Carriere — Mon, 10 Jul 2006 10:17:24 GMT

grep -v grep is the correct answer . thanks guys for th equick reply.

Re: #ps -ef | grep pmon

Bill Hassell — Mon, 10 Jul 2006 14:51:46 GMT

Actually, grep -v is not the correct answer at all. ps has dozens of options that will bypass grep and give you the correct answer. Whenever you combine grep with ps, you'll potentially get a lot of unintended matches. This is because grep has no method to look at a specific field. So in your example, you will get hits for the user "upmon" or the group called "pmons34" and also hits for the process vpmon, and so on. If the output of the grep command was fed to a kill command, you would have a mess of killed processes on your hands.

ps will match the exact name of the process, regardless of whether it was started as ./pmon or /opt/pmonstuff/bin/pmon or simply pmon. It is the C option and must be temporarily enabled with UNIX95, like this:

UNIX95= ps -fC pmon

DO NOT export UNIX95 -- just use it as shown since the variable is temporary just for ps. Making UNIX95 permanent can lead to unexpected behavior of other commands. And yes, the UNIX95= is correct -- it means defined UNIX95 as a null string.

To see how unreliable ps|grep is, try these two commands to find all the shells:

ps -ef | grep -v grep | grep sh

and

UNIX95= ps -fC sh

To make life easier, I simply alias the ps command in .profile so it is always used with ps:

alias ps="UNIX95= /usr/bin/ps"

Now you can type ps and get all the special features like -H and -o, something like this:

ps -eH

ps -C pmon -o vsz,pid,ppid,ruser,args

UNIX95 (when defined even as a null variable) turns on XPG4 behavior as defined in the ps man page.

Re: #ps -ef | grep pmon

Procnus — Mon, 10 Jul 2006 20:52:08 GMT

Personally I prefer a grep command like:
#ps -ef | grep p[m]on

Which letter gets the brackets around it doesn't matter, as long as only one charcter is bracketed.

Re: #ps -ef | grep pmon

spex — Tue, 11 Jul 2006 06:53:15 GMT

Jacques,

If my previous response gives false positives, use:

ps -ef | grep ora_pmon_ | grep -v grep

Whenever you grep for something, you need to keep in mind that grep will return any line containing the search pattern in any position. If you get unintended results, you will need to narrow down the search pattern.

Understanding the way grep works is an essential trait of any sysadmin, as it is ubiquitous in the Unix world.

PCS

Re: #ps -ef | grep pmon

Jacques Carriere — Tue, 11 Jul 2006 08:02:01 GMT

Good answers. thanks Jacques