On Thu, Dec 16, 2010 at 08:22:41AM -0500, no-re...@cfengine.com wrote: >Forum: Cfengine Help >Subject: Re: Overriding ps option string in 3? >Author: neilhwatson >Link to topic: https://cfengine.com/forum/read.php?3,19802,19811#msg-19811 > >I'm no programmer but I can't help but think that there must be a better way >to read the process table than relying on the ps utility. Perl has more than >one process table reader. How do they do it?
On operating systems that support the /proc filesystem this is typically queried directly. I know that this is true on Linux boxes, and I suspect the same is true for Solaris and perhaps others. An OpenBSD 4.1 box I have has to do something, I think via sysctl() calls, but don't quote on that. On one hand, I agree that processing 'ps' is kinda kludgy, and will impose a (slight) performance hit since you have fork/exec a process to walk the process tree, instead of just walking the process tree. On the other hand, the output for 'ps' is semi-standard, and it's "merely" a matter of string processing. Dig deeper into those perl modules, and I think you'll find that they have a combination of OS detection (for /proc), directory walking, and 'ps' output processing. -- Jesse Becker NHGRI Linux support (Digicon Contractor) _______________________________________________ Help-cfengine mailing list Help-cfengine@cfengine.org https://cfengine.org/mailman/listinfo/help-cfengine
