A Sysadmin's Worst Halloween Fears
Criswell writes "This weekend's Strenua Inertia Extravaganza comic strip deals with the fears of the system administrator... It's a special online 'exclusive'... Enjoy!"
← Back to Stories (view on slashdot.org)
the man page tells all...
:)
Berkeley syntax (aka ps aux) doenst have a dash. SysV syntax (ps -ef) does. GNU ps does both, and it figures out what syntax you are trying to use based on whether the dash is there or not. (some flags have differing usages based on if they are berkeley or SysV)
thus ps -aux whines, and ps -ef doesnt
when you pry it from my cold dead fingers!
Who's idea was it to make the ps command inconsistent when it came to handling switches and complain about using it the standard way? The dash is used so often and (otherwise) consistently that it will always be "ps -ax" to me.
AN admins worst fear is NOT zombies, it is an uber-luser with the root/admin/supervisor password. Imagine the horror: "Since Nick isn't here, I'll just install SP6 for him" or "This QSECOFR person hasn't changed their password for a long time, I'd better disable their account!".
Zombies are children that have finished executing, but their parent does not care. The parent needs to call the wait function to shut down the child properly (and transfer the exit status to the parent process).
You cannot kill such a zombie, since the parent might care at a later time. The kernel cannot know in advance when the parent is going to call wait and thus the only way to kill the zombie is to kill its parent. A zombie is merely the exit status of a program, waiting to be picked up. If you kill the parent, the kernel can finally be sure that the exit status is not being picked up, and both parent and child/zombie goes away.
You can, when you program, instruct the kernel to take care of any finished children by saying that you are never going to call wait. But you have to do that on a per-program basis, and in advance.
--