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could you please help me on my clarifications.


1). As of my understanding  if we execute any program (or) or even simple command like ls ....the process will create with the same name of the program which we executed.If 10 users run the same telnet program in a server machine it means all the processes has same name how system differentiate them...is it by different PID's?

2).What happens when we execute the sevice httpd stop... I would like to know the how the processes will be killed. IF all httpd process klled still i found some of the processes like   " root      2111     1  0 19:31 ?        00:00:00 /usr/sbin/httpd " which are root owned processes not be killed. I manually went and killed and restarted the apache then it works finally well.

[root@localhost ~]# ps -eaf | grep -i httpd
root      2111     1  0 19:31 ?        00:00:00 /usr/sbin/httpd
apache    2118  2111  0 19:31 ?        00:00:00 /usr/sbin/httpd
apache    2119  2111  0 19:31 ?        00:00:00 /usr/sbin/httpd
apache    2120  2111  0 19:31 ?        00:00:00 /usr/sbin/httpd
apache    2121  2111  0 19:31 ?        00:00:00 /usr/sbin/httpd
apache    2122  2111  0 19:31 ?        00:00:00 /usr/sbin/httpd
apache    2123  2111  0 19:31 ?        00:00:00 /usr/sbin/httpd
apache    2124  2111  0 19:31 ?        00:00:00 /usr/sbin/httpd
apache    2125  2111  0 19:31 ?        00:00:00 /usr/sbin/httpd


My Aim is to know the how init take cares of all the processes in the unix/linux system.

in the above example root owned PPID 1 that is init how it comes here i mean for the apache processes

If your parent apache process isn't cleanly dieing all the time, then it indicates an issue with your environment.

Best to look in your apache logs to see if there are any clues.

If you have orphaned apache processes after trying a clean shutdown, eg:

service apache stop
/etc/init.d/apache stop
etc

then you can clean up with

pkill httpd

Assuming your system has the pkill command.